The solar panel will be part of the half-cut-cell series recently launched by the Japanese manufacturer and the company claims it is ideal for rooftop PV projects with aesthetic requirements. The 19.0%-efficient product has a power output of 320 W.
Japanese electronics brand Sharp has launched a black, half-cut-cell, PERC, monocrystalline solar panel with a power output of 320 W.
The manufacturer said the product was intended for residential and commercial projects with aesthetic requirements
The NU-JC320B module is made of 120 half-cells measuring each 1,684 by 1,002 by 40mm. The product has power tolerance of up to 5% according to its manufacturer, with Sharp claiming the panel has a yield up to 3% higher than similar standard panels featuring full-cell architecture.
A multiple junction box design means each half of the module can function independently and the three junction boxes are each equipped with a single bypass diode in a system which is said to transfer less heat to cells, improving durability and performance.
The IEC61215 and IEC61730-certified panel features MC4 connectors made by Swiss company Stäubli and an anti-reflective front-glass coating from Canadian firm DSM. The coating, according to Sharp, reflects 1.2% less light than rival solutions.
Sharp said its module for “style-conscious commercial customers and homeowners” offers 19.0% efficiency and comes with a 25-year, linear power output guarantee and a 15-year product guarantee.
The Japanese manufacturer in January launched a PERC, monocrystalline module series featuring half-cut cells. That range followed three PERC mono products with a claimed 19.1% efficiency in April 2018. Two years ago, Sharp achieved 25.09% conversion efficiency in a cell featuring heterojunction and back-contact technology, as certified by the Japan Electrical Safety and Environment Technology Laboratories.
In a recent conversation with pv magazine Roland Valckenborg, business developer and project manager at the Netherlands Organisation for Applied Scientific Research (TNO), has described the results of a multi-year testing program for colored BIPV modules. Just a few years ago, it it was thought that power yield could be up to 50% lower than conventional panels, but tests have shown a difference of just 10%. Valckenborg says that losses can vary depending on the color of a panel.
According to Roland Valckenborg, the manager of the project, colored modules are still more expensive than traditional PV modules, but consumer interest is increasing. “People want to have a choice between different models, just as with cars,” he told pv magazine.
Valckenborg said the performance of colored BIPV modules has been underestimated. “It was such a pleasant surprise to find out in our research that the textured modules have no performance loss when compared to a normal reference module,” he claimed. “So the small losses due to the extra layer of textured glass are offset by the gain of capturing a bit more yield during low angles of incidence.”
When the first tests started in 2017, it was still believed that colored panels would reduce yield by 40% to 50%. “We demonstrated in 2018 that it is just 11% for grey modules,” Valckenborg stated.
When asked how much color affects light reflection, Valckenborg said a minimal reduction must be taken into account. “When we want a colored PV panel, we have to accept that not all the visible solar spectrum will be transmitted to the cell, but part of it will be reflected or absorbed,” he stated. In conventional, uncolored PV panels, all layers on top of the solar cells – the front glass and the encapsulant – must be optimized to be as transparent as possible, in order to allow light to be transmitted and reach the solar cells.
There are currently two main approaches to coloring PV panels: a technique consisting of pigment-based coloration, and a structural coloration method. The first technique refers to the application of dyes and pigments that mainly absorb and partially reflect specific parts of the spectrum. This is the case, for instance, with colored dots printed on the front PV glass or on colored encapsulant.
Structural coloration is obtained through the interaction of the light itself with nano-structured surfaces or multi-layer thin-film coatings. Interference filters deposited on glass exploit the interference effect to selectively reflect only a narrow portion of the visible spectrum.
The way a color is obtained, and how it affects the performance of a PV panel, therefore strongly depends on the specific technology used and the optical phenomena taking place.
“Ideally, a colored PV panel should be able to reflect only a narrow band of the visible spectrum and transmit all the rest,” Valckenborg explained. “In this way we will perceive the module with the color corresponding to that specific reflected wavelength, while the rest of the sunlight spectrum can be effectively used for power generation”
In order to avoid additional losses, the colored layer (glass or encapsulant or extra layer) should be non-absorptive, he noted.
The performance losses of colored PV are mainly due to the lower amount of photons that are transmitted to the solar cells, which in turn leads to lower current and reduced power production. Power losses for colored PV products now available on the market range from approximately 10% to 40%. Losses also strongly depend on the specific color, because each color is characterized by a specific reflection spectrum, according to Valckenborg.
“Pigment-based colors always absorb part of the spectrum. In this respect, paintings which can be considered better than others are those characterized by low absorption,” he claimed.
In terms of higher performance, interference coating is currently the best option. Filters can be made with completely non-absorptive materials, and their reflection peak can be tuned to be as narrow as possible.
“Drawbacks of this technology are more related to price and other aspects, such as the angular dependency of the color,” Valckenborg explained. “In general, a compromise must always be found between electrical performance, cost and aesthetic quality.”
One reason colored modules are still significantly more expensive than conventional panels is because the building industry is actually quite conservative, and for good reason, according to Valckenborg. As a facade element, BIPV colored modules must comply with strict safety requirements and be strong enough to avoid failures of any kind. “Because if something fails then the costs of repair can be huge,” he explained.
Colored modules are considered ideal for facade applications. “First, because facades are much more visible than roofs,” Valckenborg said. “Secondly, because the euro/m2 for a facade is already significantly higher than for a pitched roof. So the relative added cost of color is much lower for the facade application.”
Valckenborg noted that BIPV panels on pitched roofs are still a niche market.
“In the Netherlands we start to see more infrastructure integrated PV (IIPV), which includes all applications into noise barriers, dikes, and roads. Because these applications are visible, they might become colored one day,” he concluded.
Harvesting atmospheric water to cool down PV panels
Scientists from Saudi Arabia have proposed a new PV panel cooling technique which employs an atmospheric water harvester. The device uses waste heat from the PV panel to collect atmospheric water at night and then releases it during the day to cool down the module. The researchers claim the device may also be improved to produce liquid water, which could be used for the cleaning of the modules.
Scientists from Saudi Arabia’s King Abdullah University of Science and Technology have developed a cooling solution for photovoltaic panels that uses a sorption-based atmospheric water harvester (AWH).
The device, which can be placed on the back of commercials PV panels, collects atmospheric water during the evening and at night. The collected water is then vaporized and released during the day using waste heat from the PV panel as energy source. The evaporation of the water in turn takes away a significant portion of heat from the panel itself and lower its temperature.
This new solution, according to the researchers, can be applied to both small-scale PV installations and big solar parks.
“Our results show that the AWH can provide an average cooling power of 295 W m–2 when the solar cell is exposed to 1-Sun illumination, leading to a decrease in temperature of >10 °C and an increase in electricity generation of the solar cell of up to 15% relative to the solar cell without the AWH in laboratory conditions,” the research group stated. Outdoor field tests were conducted in the summer and winter in Saudi Arabia and showed that the power yield of the modules was increased by between 19% and 13%. The harvester consists of a substrate made of carbon nanotube (CNT)-embedded cross-linked polyacrylamide (PAM) and a water vapor sorbent made of calcium chloride.
The group explained that the AWH system can also be modified to produce clean water by integrating the hydrogel cooling layer within a water condensation chamber with an enlarged heat dissipation surface area. “In one experiment, an aluminum condensation chamber was attached right beneath the AWH cooling layer (dimensions 5 × 5 × 0.5 cm3), which led to a stable surface temperature of the panel of ~50 °C during the test,” it stated. Through this condensation chamber, the device may also be extended to produce liquid water, which may be used for the cleaning of the modules or simply as potable water.
The scientists added the device may be further improved by enhancing water vapour sorption–desorption kinetics, which would in turn increase its harvesting capacity and reduce material corrosion.
U.S.-based Toledo Solar is trying to distinguish itself from First Solar’s cadmium telluride dominance by operating in the residential and commercial segments, which have long been unkind to the technology.
American manufacturing of thin-film cadmium telluride (CdTe) solar panels has been the sole domain of First Solar for the last decade — but now, an Ohio-based competitor has joined the fray.
Enter Toledo Solar. Formed via a $30 million initiative led by the Atlas Venture Group, the company has set up its flagship manufacturing facility in the old Willard & Kelsey Solar Group building in Perrysburg, Ohio. Willard & Kelsey was another CdTe aspirant that fell, in part, due to First Solar’s dominance.
The facility features an annual manufacturing capacity of 100 MW and employs 25 people, with plans for the workforce to reach 70 by year’s end. The company also shares that, due to demand projections, Toledo Solar will reach an annual manufacturing output of 850 MW by 2026.
Carving a niche
And while the company posts a gaudy claim that it already has “over $800 million in purchase orders for solar panels, power converters and energy storage systems,” those orders are likely not going to become a wedge in First Solar’s market.
Unlike First Solar, Toledo Solar will be operating not in the utility-scale solar space, but rather in the residential and commercial markets.
“We recognize the void in the non-utility solar markets that have been underserved by silicon solar panels. ‘Cad-Tel’ is clearly a better option. We are excited to lead this investment in Toledo and continue to push ‘Cad-Tel’ solar technology forward,” said Aaron Bates, chairman of Atlas Venture.
The lofty claim that “‘Cad-Tel’ is clearly a better option,” is one that will be tested immediately. Toledo Solar says that the company’s panels offer 16.5% efficiency, coming in at a size of 60 x 120 cm. The panels, dubbed ‘Tier 1,’ are assumed to produce 115 W. This size, efficiency and power rating puts the panels in line with First Solar’s series 4.
“Toledo Solar has excellent technology,” said Professor Michael Heben, director of the University of Toledo’s Wright Center for Photovoltaics Innovation and Commercialization. “First Solar is the domestic leader in utility-scale solar, and Toledo Solar can fill that same role for non-utility installations.”
Toledo University, along with the Ohio Federal Research Network, were chosen to evaluate the equipment and technology at the location in Perrysburg, Ohio.
“The degree of differentiation is likely very small and to a large degree necessitated by the intellectual property space First Solar has made off-limits to competitors,” thin-film expert Markus Beck told pv magazine.
He said that the back contact could have some level of differentiation, as could the module architecture, albeit to a lesser extent.
On April 9, 2020, A+ Solar Solutions finished the installation of a 9020 Wp solar array with 22 LG410N2W-V5 High-Efficiency NeON® 2 modules and 22 Enphase IQ7+ inverters.
A+ Solar Solutions installed 14 LG410N2W-V5 High-Efficiency NeON® 2 modules in portrait position on the southwest-facing roof of the kitchen and 8 LG410N2W-V5 High-Efficiency NeON® 2 modules in landscape position on the southwest-facing roof of the garage.
All 22 modules are connected to the grid via 22 Enphase IQ7+ microinverters and can be monitored via Enphase Enlighten on a computer, tablet, or smartphone.
Enphase provides an industry-leading 25-year warranty on its IQ7+ microinverters.
LG provides a 25-year product warranty on their LG410N2W-V5 High-Efficiency NeON® 2 modules as well as a 25-year production warranty. Where the average solar panel degenerates roughly 20% in 25 years, the LG410N2W-V5 High-Efficiency NeON® 2 modules only degenerate 9.9%.
Four days after receiving the ballast for the 22,120 Wp solar array, A+ Solar Solutions finished the mechanical part of our customers 56-panel solar array.
The 56 panels Hanwha QCells Q.PEAK L-G5.2 395W solar panels are mounted on 56 EcoFoot 2+ frames and fixed on position by 630 ballast blocks.
Apart from the 12-year product warranty, Hanwha QCells guarantees the Q.PEAK L-G5.2 395W solar panels will produce no less than 85.0% of their nameplate power output after 25 years.
The 22,120 Wp solar array is connected to the grid by 28 YC600Y microinverters from APsystems. The YC600Y fro APsystems is a single-phase, smart grid-compliant microinverter, that serves two solar modules with dual, independent MPPT.
Because solar arrays last for 30-35 years and require hardly any maintenance – cleaning the solar panels once or twice a year is preferred – investing in a solar array is a very safe investment. It will make you untouchable for all the hikes in electricity rates to come and will provide free, clean energy for 30-35 years.
SkyBox Hybrid Inverter AC Coupling update from OutBack Power leverages existing solar arrays to provide backup and energy management
Faced with extreme weather events and unexpected and planned power outages, flexible energy storage solutions provide solar array owners with backup power from batteries when the lights go out. Recently, OutBack Power™ released an AC coupling firmware update to its SkyBox™ hybrid inverter. AC coupling is ideal when users have an existing solar PV system and want to add batteries for backup and time-of-use energy management.
“The SkyBox hybrid inverter is a fantastic solution for owners of grid-tied PV systems,” said OutBack Power™ trained installer Jason Rutland, Vice President of Sales and Marketing at United Electric and Solar in Camarillo, California. “SkyBox does not require much of the existing grid-tied system be replaced compared to what is required with a DC-coupled solution. That is one reason why I believe we are going to see more demand for the SkyBox AC Coupling function as we experience more outages in our region.”
Public Safety Power Shutoffs last year left millions of California residents in the dark, with little or no notice. While many households and businesses expected their solar panels to power their buildings when the grid was down, they now understand the reality that they need a capable backup battery system to supply power during these shutoffs in order to realize the full potential of their solar power system. By adding a SkyBox™ hybrid inverter and energy storage to an existing grid-tied PV system, owners can keep their arrays and even enlarge them, meet new code requirements, and power their buildings with clean energy.
Since last year, new solar customers in California have been put on Time-of-Use rates with peaks in the evening when solar production is declining. In addition, new National Electric Code (NEC) requirements took effect in California and other regions in 2017. Notably, new rapid shutdown requirements are now being enforced, raising the cost of replacing an existing inverter and/or PV array.
OutBack Power’s SkyBox™ hybrid inverter with AC coupling provides the solution to both problems. Once the SkyBox™ hybrid inverter and batteries are installed, an icon appears on the SkyBox screen whenever a new firmware version is ready for installation. The user can simply press the icon and follow the simple on-screen instructions to install the firmware. A true hybrid energy system, SkyBox™ hybrid inverter provides both reliable energy back-up in the face of utility shutdowns and helps customers navigate new pricing structures and electrical codes with their existing arrays intact. Simply, SkyBox addresses a need in the market for energy flexibility.
“Today, many customers expect more control over how they use their power. This is essential in the event of unexpected power shutoffs, or rate-changes,” said Paul Dailey, Director of Product & Market Strategy for OutBack Power™ “By providing an easy AC coupling solution for systems up to 7.6 kW, we are giving users more control of their systems, more energy savings, and more protection in the face of shutoffs.”
OutBack Power™ updates its SkyBox hybrid inverter firmware regularly to introduce new features. Past firmware upgrades include stacking, to allow two SkyBox™ hybrid inverters to be used in the same system, drop-down battery presets for streamlined installation and external current measurement which enables energy management for the whole home. This last feature eliminates external charge controllers and communication boxes, significantly cutting solar and energy storage installation time and cost. For more information on the SkyBox™ hybrid inverter, visit http://www.outbackpower.com/products/item/skybox.
About OutBack Power Technologies, Inc.
For over 18 years, OutBack Power Technologies, Inc. has been the recognized leader in the design and manufacture of battery-based renewable energy systems. With the regulatory and incentive landscape changing almost daily, consumers are rapidly moving away from simple grid-tied systems and towards intelligent, battery-based designs that blend energy independence with smart home technology that is good for the budget and the environment.
Now part of EnerSys, OutBack Power Technologies, Inc. is backed by the resources and expertise of the global leader in stored energy solutions. Whether the application is village micro-grids in Africa, rural electrification projects in Latin America, remote off-grid cabins in Alaska, or a suburban home in California, OutBack Power Technologies, Inc. has set the bar for delivering advanced renewable energy power conversion electronics and energy storage. For more information, visit www.outbackpower.com.
EnerSys, the global leader in stored energy solutions for industrial applications, manufactures and distributes reserve power and motive power batteries, battery chargers, power equipment, battery accessories and outdoor equipment enclosure solutions to customers worldwide. Motive power batteries and chargers are utilized in electric forklift trucks and other commercial electric-powered vehicles. Reserve power batteries are used in the telecommunication and utility industries, uninterruptible power supplies, and numerous applications requiring stored energy solutions including medical, aerospace and defence systems. EnerSys provides highly integrated power solutions and services to broadband, telecom, renewable and industrial customers. Outdoor equipment enclosure products are utilized in the telecommunication, cable, utility and transportation industries, and by government and defence customers. The company also provides aftermarket and customer support services to its customers from over 100 countries through its sales and manufacturing locations around the world. For more information about EnerSys and its full line of products, systems and support, visit www.enersys.com.
Ossiaco has built the one Home Solar Inverter to rule them all
Ossiaco has developed a new inverter that it believes will truly revolutionize the worlds of residential energy management, solar, and EV charging in one fell swoop. As a privately-owned and funded company, Ossiaco has been flying under the radar for some time now, but we spoke to the leadership team and it is clear the team is perched at the edge of the cliff, ready to take the plunge into the market at scale.
Ossiaco’s CEO Marc-André Forget told me about the new residential DC charger the company has developed and how the company was primed to make a big move into the market. Then he dropped the price. At US$5,000, the charger is far from affordable on the surface, but he just smiled and kept going. If the team at Ossiaco can deliver on the full potential of the technology it is working with, the new device has the potential to be a complete game-changer in the world of distributed energy resources (DER), delivering unparalleled value to homeowners.
The Best of All Worlds
Ossiaco started with the seemingly simple mission of enabling life without compromises. They are technologists, passionate about the potential of renewables and saw an opportunity in the host of challenges associated with integrating renewables into the home and the grid pose. Adding solar should not mean having to manually adjust the time you plug your vehicle in to charge to utilize the solar being generated. People should be able to plug it in when it’s convenient and let the software do the heavy lifting. They envisioned faster charging at home for those looking for the ability to rapidly refill their vehicles.
The hardware evolved as they explored the natural synergies between the various technologies in the residential new energy space. Imagine it like working with a bunch of new sets of LEGOs. Ossiaco’s team took the dozen or so technologies found in a fully loaded renewable households as the LEGO building blocks including inverters, rapid shutdown devices, EV chargers, and broke them down into their constituent components.
From there, they tossed them into a room with some of their best engineering talent and after enough blood, sweat, and tears, the Ossiaco dcbel was born and brings together what they see as the best of all worlds. The magic of Ossiaco’s $5,000 residential DC EV charger is that it isn’t just an EV charger. It leverages what is otherwise a simple inverter and leverages it as the heart of the home energy system.
The Ultimate Home EV Charger
First and foremost, dcbel is a dual nozzle, bi-directional DC EV charger. That’s a mouthful, so let’s unpack it. It comes with two EV charging nozzles that can crank power into the car. One is a DC charging nozzle (either CHAdeMO or CCS) that can add up to 60 miles of range per hour. The second is more of a standard level 2 EV charger, but the fact that this single device already performs two functions for a new energy household is a great start. In our home, just this functionality alone would replace the two level 2 EV chargers.
The DC charger allows for bi-directional charging, meaning compatible vehicles can gulp down power from the home into the battery, then push it back into the home if needed. Vehicle-to-grid and vehicle-to-building tech isn’t being leveraged by many automakers or utilities yet, but it’s great to have a device that has an eye to the future rather than both feet planted firmly in the inflexible past.
Sunshine? Sure, I’ll Take It
The humble dcbel charger Marc-André told me about is also able to convert the DC generated by a rooftop solar system into the AC power most homes run off of. That alone is not exceedingly special, but remember, this thing started out as an EV charger. Eliminating the inverter or inverters required for a solar system and consolidating the functionality into what we’ll call an EV charger is more than just cleaning up the installation, though it does that as well.
More importantly, it eliminates the need to install one or two more devices in the home. In our brand spanking new, high tech, state of the art Tesla Solarglass Roof installation, the functionality included in dcbel (so far) would take us from 4 devices on the wall down to 2 and that’s saying nothing of the wiring, junction boxes, circuit breakers, and fuses in between.
The improvements translate to savings at the bottom line and a faster installation. That’s meaningful to both the solar installer and the homeowner, who can both enjoy closing the deal and getting the system up and running even faster.
A Resilient Home
After being routed by wildfires over the last few years, California utilities implemented Public Safety Power Shutoffs that can cut grid power anywhere from a handful of hours up to a couple of months at a time. That instability in and of itself creates perhaps the strongest case possible for adding solar and energy storage to a home.
dcbel was built to improve the integration of renewables into the home and to maximize the benefits a homeowner is able to realize as a result. A key component of the renewable home of the future is energy storage and the team at Ossiaco see the massive battery in EVs and built the bi-directional dcbel to tap into that power.
When the grid is humming along nicely, rooftop solar generation flows into the home, into the EV, and to the grid without a second thought. But, in the unlikely even the grid goes down, dcbel is able to tap into the power stored in the EV’s battery to power the home. If the grid outage extends beyond the capacity of the EV battery, homeowners can drive to an EV charger to top up, extending the ability to run without grid power.
Store It, Use It, Send It
The efficiencies of consolidating so many appliances into a single appliance that does it all is huge and that would be worth a new product by itself, but Ossiaco didn’t stop there. Everything they built into dcbel up to this point in the article already exists. They took dcbel a few steps further with true intelligent home energy management with the capability to tap into an existing energy storage system.
The system can also optimize the DC power and funnel it directly into an EV battery. Enabling the optimal flow of current to the destination that makes the most sense at the time is one of the key achievements of Ossiaco’s new device. Eliminating unnecessary conversions from DC to AC and back to DC improves the overall efficiency of the home electrical system.
Ossiaco’s single device can replace the traditional solar inverter system and two home EV chargers with a single device that is then supercharged with Ossiaco’s home energy management software. That’s what the world of residential new energy systems needs right now. We have all the components to let homeowners generate and store their own power, but the market is missing the product that sits at the center and transforms all of the players and their instruments into a beautiful orchestra.
A New Paradigm
At its core, Ossiaco is a tech company that melded together its mastery of inverters with an impressive array of algorithms in a single product that cleans up the home powered by renewables. The company was founded by a team of revolutionaries who saw the potential for uniting the worlds of EV charging, solar inverters, and energy storage into a single, intelligent smart home energy manager with experience working at multinational corporations who took the leap into the unknown seven years ago.
Together, they created a disruptive new product that takes a bold leap forward into the renewable, resilient future we all want, smoothing over the seams between them, streamlining the installation, and eliminating complexity in one fell swoop. It also saves homeowners a ton of cash along the way. It turns out that Marc-André was right when he said dcbel was an affordable EV charger at $5,000. If anything, he was downplaying what the team at Ossiaco has achieved.
Ossiaco’s dcbel is slated to launch in summer 2020 and with the price tag sitting at $5,000 for a 15.2kW solar inverter, bidirectional DC EV charger, AC charger, backup manager, and the intelligence that makes everything play nicely together. Given the significant improvements it brings to the world of renewables, EV charging, blackout prevention, and intelligent home energy management, I expect it to be in high demand.
New solar energy innovations are being unveiled at Intersolar 2020 in San Diego this week, including the California launch of a concrete solar shingle, a unique under-the-panel battery storage configuration, and a single-axis tracker that can accommodate a 10% grade on undulating sites. And one forward-looking company is now buying up broken solar panels in expectation of mining the components for recycling.
The parade of international technology at the ISNA2020 show continues to demonstrate that the solar industry is getting technologically smarter while it thankfully gets cheaper. This is particularly good for both residential and commercial solar installs since utility-scale solar seems to have bottomed out with low-ball, long-term power purchase agreements.
An Integrated Concrete Solar Shingle Comes to California
One standout new offering at the trade show is the Ergosun solar shingle, which looks much like a slate roof tile, but can gather both direct and low-light sun rays. The waterproof concrete base is lapped to be waterproof and is sturdy enough to withstand major snow loads, like those in Norway, where the company recently performed its first install, according to Bruce Wintemute, Solarmass Energy’s chief operations officer.
shingles generate 15 Watts per tile, which is a 60% gain in yield compared to a
standard silicon wafer solar panel taking up the same square footage of space,
the company claims. It features a patented two-piece junction box and comes in
The shingles are manufactured both in Canada and China for the US market and carry a warranty of 80% of peak power after 25 years. The Ergosun Integrated Solar Roof Tile was engineered in the UK and now generates power on homes in Canada, the United Kingdom, Sweden, South Africa, and Jamaica.
Energy Unveils Under-The-Panel Battery Storage
Startup Yotta Energy unveiled its SolarLeaf, a battery storage system located under a traditional solar panel, a modular Direct Current-based storage solution with smart passive thermal regulation to protect the batteries from high heat. The battery chemistry is based on the lithium-iron-phosphate solution that has extremely low chances of fire risk, and does not contain cobalt or magnesium that is present in other battery chemistries, notes Sean Walters, the director of business development for the company.
SolarLeaf includes a built-in DC optimizer with wireless monitoring to manage
both solar power generation and energy storage. The DC coupling means that no
energy loss takes place as in systems where the DC current is converted to AC
for household use, and then reconverted to DC to charge batteries, which
involves an energy conversion efficiency loss of several percents in each stage.
Since the battery is located under the panel, rather than being housed in a
cabinet that might take up critical ground or wall space, it offers a unique
solution for applications like carports, where battery cages on the ground
could be bumper bait.
Sunflower Solar Tracker Rides the Hills
Another innovation at the show is the addition of a ballast-mounted version of the Sunflower single axis tracker from RBI Solar, which can be installed on an undulating 10% grade. The tracker was launched just one year ago, but garnered 500 megawatts of installation during 2019, says Kevin Ward, the marketing manager of the company.
The precast concrete ballast version of the Sunflower permits installation over landfills, culturally sensitive sites, and other locations where ground penetration is either not desirable, or not permitted. The linkage of the patented gearbox for the tracker is positioned such that weight is carried by the post, rather than on the gear, which helps prevent the wind-induced torque that is referred to as “galloping” in the industry.
advantage of the steep slope climbing capability of the tracker is that ground
preparation costs are largely eliminated, opening up the geographic market for
the technology to locations that previously would not have been considered
suitable for a tracker system. The centralized tracker system accommodates up
to 120 modules per row.
Harvests Dead Solar Panels
A little-known fact in the solar industry is that the metallic and chemical components of solar panels would be considered hazardous, if the public were exposed to the compounds, points out Dwight Clark, the chief compliance officer for WeRecycleSolar, which is actively buying decommissioned solar panels at the show.
“About half of the state environmental agencies would classify solar panels as hazardous waste,” Clark says. “So we have developed a process to separate out the 98% of the components by weight and to provide them to the international market for commodities,” he says. WeRecycleSolar has just completed Phase One of its process testing, and hopes to begin commercial operation within four months. The limiting factor will be having enough panels on hand — or about 100 tons — to justify the recovery line, he says. One solar panel weighs roughly 50 pounds. The company has found a way to recover all the standard components of a solar panel except the plastic back sheet
In 1989, pro-nuclear lobbyists claimed that wind power couldn’t even provide 1% of Germany’s electricity. A few years later, pro-nuclear lobbyists ran ads in German newspapers, claiming that renewables wouldn’t be able to meet 4% of German electricity demand.
After the renewable energy revolution took off, in 2015, the pro-nuclear power “Breakthrough Institute” published an article claiming solar would be limited to 10–20% and wind to 25–35% of a power system’s electricity.
In 2017, German (pro-nuclear power) economist Hans-Werner Sinn tweeted that more than 50% wind and solar would hardly be possible. And in 2018, Carnegie Science reported a study claiming that “wind and solar could meet most but not all U.S. electricity needs.” According to one of the authors, their research indicates that “huge amounts of storage” or natural gas would need to supplement solar and wind power.
From a pro-renewable perspective, this is encouraging. The claims about the limits of renewable energy have moved from “not even 1% of electricity” to “most but not all of the electricity.” And yet, the anti-renewables message has always been the same: renewables will lead to a dead end.
In order to underscore their point, anti-renewable energy propagandists now publish incorrect cost figures that claim a fully renewable electric grid would be unaffordable or way more expensive than other options, such as, you guessed it, nuclear power.
MIT Technology Review writes about the “scary price tag” that such a purely renewable grid would come with, calculating $2.5 trillion as a price tag for storage requirements alone — 12 hours of storage. Wood McKenzie also talks about $2.5 trillion, albeit for 24 hours of storage. The “Clean Air task force” puts the cost for a 100% renewable grid in California at an annual $350 billion.
Anti-renewable propagandists need to talk about imaginary high costs of renewables, especially because one of their preferred ways of generating electricity — nuclear power — turns out to be incredibly expensive.
Renewable energy gets cheaper each year, nuclear power gets more expensive each year — how come they still adamantly claim that renewables are not a cost-effective way of decarbonizing?
The answer, of course, is that the studies are flawed. Taking a look at these studies shows that several patterns can be observed in many of these studies. Among these flaws are ridiculous overestimates of storage requirements, overestimates of grid expansion needs, and the insistence on uneconomical strategies of storing electricity, such as insisting on batteries to store several weeks worth of grid electricity consumption.
In order to understand how these studies are flawed, it’s essential to understand how a renewable energy grid actually works, how energy storage works, and what costs you can expect. After that, I will describe the flaws in some of these studies and recalculate a more realistic scenario, especially more realistic cost projections.
How a renewable grid works
A few facts are important to know:
Storage will not be necessary for a long time.
The sun doesn’t always shine, the wind doesn’t always blow — yet most of the time, there is either sun or wind available. For now, storage will not play a role for a long time. Solar and wind power will increase their shares of electricity consumption, and until they reach 80% of electricity consumption, grid expansion, moderate curtailment, and gas-fired backup power plants are the only tools necessary to reach such a high share of renewables.
Backup power plants are cheap.
So, if 80% of the electricity is generated using solar and wind power, the remaining 20% has to be created from backup power plants. According to grid operator PJM’s data, backup power plants cost up to $120,200 per megawatt per year. We can calculate the cost for a worst case scenario: To cover the 769 gigawatts of US peak load, backup power plants would cost $92.5 billion per year. Divided by the 4.18 trillion kilowatt-hours that were consumed in the USA in 2018, that amounts to 2.2 cents per kilowatt-hour.
Nuclear power is expensive and gets more expensive over time.
The newest Lazard figures put nuclear power at 15 cents per kilowatt-hour. In addition, that’s more than the cost figures of the previous years.
Even for 80 percent solar and wind, grid investment costs are moderate.
The NREL estimates that, even if you get 77% of electricity from solar and wind power, the grid will have to be expanded from around 85,000 gigawatt-miles to around 116,000 gigawatt-miles. That’s not even a 50% increase.
Getting more solar and wind power will require overbuilding and curtailment.
One study that is often cited as “proof” of the limits to renewables finds that, actually, even without any storage, overbuilding solar and wind to 1.5 times US consumption could get you 93% solar and wind power in the grid. This is still without any storage at all. To put this into perspective, if you overbuild solar and wind power 1.5 times, and you have an LCOE of 3 cents per kWh (according to BNEF, this is possible for solar and wind by 2030), that gives you a total LCOE of 4.5 cents per kWh (ignoring minor system costs for curtailment), which is still very cheap, and far below the 15 cents per kWh figure for nuclear power.
The remaining 7% could be provided, for example, by burning synthetic methane that’s made from hydrogen and carbon dioxide.
You can make a synthetic gas that’s 100% compatible with the existing gas infrastructure. The process is known as power-to-gas. Electrolysis uses solar and wind electricity to split water into hydrogen and oxygen. In a second step, carbon dioxide, which can be captured from the air (direct air capture) is mixed with the hydrogen. This results in methane, which is 100% compatible with the existing gas grid and the gas-fired power plants. Once this methane is burned, it emits only as much carbon dioxide as was previously captured from the air. The cost for this methane is currently estimated at 20 euro-cents per kWh, but costs have come down in the past and will continue to come down. In Germany, there is already a facility that generates renewable methane and injects it into the gas grid.
There might be other storage options as well in the future.
To store the entire grid for many hours or even days, batteries are too expensive. Yet there are other options under investigation. Siemens is testing a simple concept of first converting the electricity into heat, storing the heat, and later using that heat to drive a steam turbine. Highview Power uses cold air to store electricity and use the expanding, reheating air to drive a turbine. Both companies already built a pilot storage plant.
Considering these facts, it is possible to make a calculation about how much a purely renewable grid would likely cost, using today’s technology and today’s prices. Whenever anyone claims way higher costs, we should grow suspicious immediately.
Calculating the cost for a purely renewable grid.
Assuming we used today’s technology, we can compare solar and wind power to nuclear power. According to Lazard, nuclear power costs 15 cent per kWh. Generating all of US electricity from nuclear power, therefore, would cost $615 billion per year. So, how much would a completely renewable grid cost — per year and per kilowatt-hour?
One way a renewable grid would work would include the following technologies
Expanding solar and wind power to reach 93 percent wind/solar.
Using the study “geophysical constraints on the reliability of wind and solar power,” getting to 93 percent solar and wind power would require generating 1.5 times US power demand. This means that you overbuild wind and solar and curtail some of the electricity to increase the amount of solar/wind power that can be used directly. You would have to generate 6300 TWh of renewable electricity, which at current costs (according to Lazard) would cost $271 billion per year.
Paying for backup power plants.
Backup power plants that could provide the entire grid with electricity would cost $92.5 billion per year, according to PJM data.
Expand the grid
NREL data suggests that you need +30 TW-miles to go to 80 percent renewables. Extrapolating, you would need +37.5 TW-miles for 100 percent. That’s around 60 TW-km — thus, around $60 billion grid investment. Calculating the grid investment cost per year, it would cost around $10 billion a year (WACC 10%, 10 year payment). This shows that grid expenditure is negligible.
Burning renewable methane in these backup power plants to reach 100 percent renewable electricity
Using the latest study by Ludwig Bölkow Systemtechnik, generating synthetic natural gas from hydrogen, using direct air capture for the carbon dioxide, 1 kWh of synthetic methane costs around 20 euro-cents per kWh when produced in Europe. In a 60 percent efficient CCGT power plant, 1 kWh would cost 33.33 euro-cents (37.15 US cents). Generating 7 percent of US electricity from renewable synthetic methane costs $110 billion.
Total cost, therefore, would amount to $483.5 billion per year. Divided by electricity consumption of 4100 TWh, the total cost would be 11.8 cents per kilowatt hour. This is already cheaper than Lazard’s estimate for nuclear power, which is currently at 15 cents per kilowatt-hour.
Let’s also stress that this will change. In 2030, according to BNEF, wind and solar power will already be below $30 per MWh. Synthetic methane will cost around 15 euro-cents per kWh, according to LBST. As such, you would annually spend $189 billion on wind/solar electricity, plus 27,86*294= $82bn on synthetic methane, $92.5 bn on CCGT power plants, and $10 bn on grid expansion leading to a total $9.1 cents per kWh. That’s way cheaper than nuclear power.
So, how come we keep reading that a fully renewable electricity grid would be astronomically expensive, especially from pro-nuclear lobbyists? If a quick and dirty calculation already shows that renewable electricity is already cheaper than nuclear power, how come numerous studies point to 100 percent renewable electricity being unaffordable?
Once you understand how a renewable grid works and how much it will likely cost, we can look at the strategies used to discredit renewable energy.
Let’s look at the studies.
One of the studies frequently quoted by MIT Technology Review is the study “Geophysical constraints on the reliability of solar and wind power in the United States.” It’s available on the Internet for free, and a seemingly serious attempt to calculate scenarios of reaching 100 percent renewable electricity. Using 36 years of weather data and comparing it to US electricity demand, the study finds that:
80 percent of the US electricity could be provided by wind and solar power if either
12 hours of storage were installed or
there were a continental-scale transmission grid.
To achieve 100 percent solar/wind power, either “several weeks worth of electricity storage” and/or “the installation of much more capacity of solar and wind power than is routinely necessary to meet peak demand” would be required. The availability of “relatively low cost, dispatchable, low CO2 emission power” would obviate the need for extra solar/wind and/or energy storage.
So far, that’s nothing new.
This study, however, goes on by calculating the cost of various scenarios of going to 100 percent renewable energy. However, none of the scenarios considered is even remotely as economical and/or realistic as a solar/wind/backup power plants/power-to-gas scenario. Instead, the study only considers 3 options, which are:
overbuilding (no storage)
pumped hydro storage
There is no precise data on the annual costs for these options, yet it is mentioned that the costs would be $2.7 trillion, the assumed battery life would be 10 years, and the assumed discount rate would be 10 percent — which implies annual costs of $440 billion.
No reason is given why power-to-gas would be completely ignored, at a time in which it was already considered a required future technology to reach 100 percent renewables in Germany. Even precise cost data was already published in Germany (Potenzialatlas Power to Gas). Compared to today, power-to-gas was significantly more expensive at the time the study was published (and so were backup power plants to burn that gas), yet the total costs of storing electricity would have been significantly cheaper.
To get 93 percent solar/wind without storage, generating 1.5 times demand (6000 TWh) would be necessary — at that time around $270 billion. Power-to-gas (synthetic methane) to cover for the remaining 7% would have cost $185 billion, gas-fired power plants would have cost $150 billion. Total cost would have been around $600 billion. This is roughly on par with what nuclear power costs today.
To use batteries, $430 billion would have been necessary for storage alone, in addition, you would have had to generate 8000 TWhs of electricity, leading to a cost of $790 billion. This is equivalent to almost 20 cents per kilowatt-hour in cost.
Therefore, that study calculates a scenario which generates around $190 billion a year in unnecessary costs. In addition, that scenario today is outdated. As already calculated, today’s technology would lead to an annual cost of $483.5 billion. The Caldeira study, therefore, calculates a scenario that is $300 billion per year too expensive. The study is outdated, assumes the use of inadequate technology and therefore shouldn’t be of any relevance any more.
The Clean Air Task Force Study for California
In case you thought a study like the Caldeira study was highly misleading, you haven’t seen the CATF study for California. As expected, this study was reported on by MIT Technology Review as well.
The study assumes that for 100 percent renewable electricity, California alone would have to pay an annual $350 billion for storage alone. This is akin to $1.6 per kilowatt hour. As expected, that study is complete nonsense, but how on earth are such insane figures even calculated and argued for?
The most likely explanation is that this study completely ignores the possibility of overbuilding and curtailment. This is especially problematic in California, because both wind and solar power plants produce less electricity in winter. The most obvious approach to address that problem would be to build enough wind and solar power plants to provide enough electricity in winter. In summer, excess electricity generation would have to be curtailed.
Instead of this obvious approach, it appears that the Clean Air Task Force assumes that California will build giant batteries that can store all excess electricity in summer to save it for winter. Such an approach is completely absurd, as is demonstrated by the price tag of $350 billion for California alone.
Using up-to-date figures we can estimate the actual cost for California. To reach 100 percent renewable energy using solar, wind, and power-to-gas, we can estimate a total cost of $42.4 billion a year. This is akin to an LCOE of 18.4 cents, using current technology. This is still rather expensive, but not much more expensive than nuclear power. Considering the rapid cost declines for solar and wind power, it can be assumed that solar, wind, and power-to-gas will turn out to be the more economical solution for California as well.
The Hans-Werner-Sinn study for Germany
A similar study was already published in Germany, again assuming one scenario in which curtailment was not allowed. So, again, you had to store huge amounts of electricity in summer to save it for winter — 16 TWh of storage altogether to reach 89 percent solar and wind power. The second scenario didn’t allow for storage at all, which made a massive overcapacity necessary. Therefore, 61 percent of wind and solar power would have to be curtailed to reach 89 percent solar and wind power. There already is a rebuttal to that study, published by Zerrahn, Schill, and Kemfert, that showed how a compromise (allowing for 22 percent curtailment) would reduce storage needs to 1 TWh, whereas allowing for 32 percent curtailment would furthermore reduce storage needs to 432 GWh.
The Wood MacKenzie Study
Wood MacKenzie published a white paper, Deep Decarbonization requires deep pockets, estimating capital investment costs of $4.5 trillion for decarbonization using wind, solar, and batteries alone.
The Wood MacKenzie assumptions are the following:
1,600 gigawatts of generation (wind and solar)
24 hours of lithium-ion battery storage
200,000 miles of new high-voltage transmission at overall $700 billion in cost.
Wood MacKenzie’s assumptions are partly in contradiction to the “geophysical constraints” study. It suggests increasing solar and wind power roughly 12.3 fold, which means that there would be no overbuilding at all.
There is little indication that this would suffice to get 100 percent of solar and wind, even if you had 24 hours of battery storage (unlike 12 hours as suggested by the Caldeira study). In fact, the supplementary data provided by Caldeira shows that increasing storage capacity from 12 hours to 24 hours would have little effect on the necessity to overbuild solar and wind power plants. Since battery storage is incredibly expensive, Wood MacKenzie suggests using:
an inadequate storage strategy
unnecessarily much storage
likely too little solar and wind power to actually achieve 100 percent solar and wind.
Even less justifiable is the assumption that $700 billion would have to be invested in grid expansion. Based on NREL data, it’s likely that less than one tenth of that sum needs to be invested. Even the Caldeira study “only” talks about $410 billion of grid investment.
The Jenkins–Thernstrom commentary
Jenkins, former Director for Energy and Climate Policy in the Breakthrough Institute, published one study and one commentary in Joule Magazine, which of course found that a purely wind-solar-storage solution is not a good idea. Jenkins co-authored one study and one commentary on the future of electric grid decarbonization. The study was published in November 2018, the commentary in December 2018.
The commentary points out challenges on the path to a zero emissions grid. It correctly finds that the challenges increase as renewable penetration increases. It also correctly finds that grid expansion cost are negligible compared to other costs and that greening the electricity sector is vital to green the economy.
It correctly finds that there is a necessity to overbuild. However, it finds that between 40 and 50 percent of generated electricity would have to be curtailed and finds that this would almost double the costs of the entire electricity system. This is, of course, completely outdated, since electricity from solar and wind power have fallen drastically in costs.
The study specifically mentions a possible electricity consumption increase for electricity “and fuels produced from electricity, e.g. hydrogen,” to more than 50 percent of final energy demand.
However, oddly, the study completely ignores the possibility of using exactly these fuels to green the electric grid. Producing electrolytic hydrogen and converting it to methane is not considered, arguing that “considerable uncertainty remains about the real-world cost, timing, and scalability of these storage options.” This technology (power-to-gas), which significantly reduces the costs of greening the electric grid, is completely dismissed.
There is no clear definition of “considerable uncertainty,” and Jenkins, Luke, and Thernstrom don’t mention any specifics or any studies that point to that. In fact, in 2018, various German studies (such as the DENA e-fuels study) already were very specific about the cost (and also predicted a significant cost reduction). No reason is given why that data would be completely ignored.
The commentary goes on arguing that several technologies (grid expansion, flexible demand, seasonal storage, and very-low-cost wind and solar) must all become reality, whereas other technologies such as nuclear power, CCS and enhanced geothermal energy could all fill the firm role in a low-cost, low carbon portfolio. Therefore, the commentary argues, the chances of wind, solar and storage providing 100 percent of electricity consumption are lower than the chances of wind, solar plus nuclear, CCS, or geothermal energy.
This logic has a severe flaw. First of all, very-low-cost wind and solar are very likely to become reality and partly already are reality. Just because several conditions have to be met in one scenario doesn’t mean that this scenario is less likely to work out. Jenkins writes about nuclear power, CCS, bioenergy, and enhanced geothermal energy: “Assume that each resource has only a 50 percent probability of becoming affordable and scalable within the next two decades. If all four options are pursued, however, the odds that at least one succeeds would be 94 percent.”
But you cannot do that. You cannot simply assume a certain chance. Jenkins says that these examples are “purely illustrative,” but still goes on arguing that we shouldn’t eschew the development of firm low-carbon technologies because they face challenges today.
But that’s not how it works.
To make wind and solar power cheap, to make batteries cheap, hundreds of billions of dollars had to be invested. We don’t have an infinite amount of money and an infinite amount of time. Should we invest hundreds of billions of dollars in nuclear power, CCS, and geothermal each? This is money that we couldn’t use for making wind and solar power and energy storage — all of which are proven and highly developed technologies —even cheaper. The more time and money we waste on technologies that face severe problems and are expensive, the less time and money we can use for solar, wind, and energy storage — technologies that actually work.
The Jenkins–Sepulveda–Sisternes–Lester study
Again, this study points out a barely new “finding” that a grid that merely consists of batteries, solar, and wind power is likely going to cost more than other alternatives. This is well known. This is exactly why there is investment in power-to-gas and other long-term storage technologies — for example, thermal energy storage.
Of course, again, power-to-gas is ignored entirely, therefore leaving wind-solar and storage with the only storage option of lithium-ion batteries.
What’s more worrisome about this study is the fact that the authors “propose a new taxonomy that divides low-carbon electricity technologies into three different sub-categories: ‘Fuel-saving’ variable renewables (such as solar and wind), ‘Fast burst’ balancing renewables (such as lithium-ion batteries), and ‘firm’ low carbon resources such as nuclear power plants and carbon capture and storage (CCS) power plants.”
This is a very dangerous taxonomy. If we start using it, we implicitly rule out that solar, wind, and some sort of energy storage can power the grid alone. Solar and wind power will always merely be considered an add-on to a grid that is essentially powered by some other resource.
Of course, power-to-gas could be considered a “firm” energy source. However, there is a significant difference between carbon capture and storage (CSS) and nuclear power: capital costs. Equipping a gas-fired power plant with carbon capture features would double the capital costs, which reduces its economical prospects if it isn’t used frequently. Nuclear power is even more capital-intensive and would have to be used frequently as well.
This is also confirmed by what the authors envision: What’s officially named “mid-range scenario” (presumably the most likely outcome, according to the authors) not only indicates that nuclear power will be the most important electricity source — providing around 50 percent of all electricity in the “Southern System” and around 80 percent electricity in the “Northern System.” Jenkins basically did it again: Limit wind and solar power to a maximum of around 50 percent and declare that the most important electricity source in the future will be — you guessed it — nuclear power.
However, looking at the study, you will immediately find significant flaws.
The first obvious flaw, of course, is that power-to-gas is completely ignored. This was expected.
A little less expected are the assumptions for technology costs.
For example, the mid-range costs for solar power are considered to be $900 per kilowatt. This is based on the NREL data for 2017, applying 50 percent cost reduction. In the “Very Low” scenario, solar is assumed to cost $670 per kilowatt — based on the NREL’s estimates for 2047 (Utility PV — Low).
As for wind, mid-range costs are considered 25 percent under the NREL’s “low” assumption for 2017 wind power. “Very low” wind power costs are assumed to be $927 per kilowatt — based on NREL’s estimates for 2047 wind power — (Land Base Wind, TRG 1 — Low).
At the same time, the “Conservative” assumption for nuclear power is $7,000 per kilowatt, based on Georgia Public Service Commission (PSA).
$670 per kW for solar in 2047 are likely way too pessimistic. DNV-GL, for example, now estimates that solar PV would be at 42–58 US cents per watt in 2050. The most optimistic “very low” scenario for solar, therefore, should be at $420/kW, not $670/kW. Wind energy forecasts are more conservative. Thus, wind energy projections made by Jenkins might be correct.
But taking a look at Jenkins’ envisioned grid supply, in most high-renewable scenarios, the largest part of the renewable electricity is provided by solar power anyway. Thus, underestimating the reduction of solar energy costs means to decisively overestimate total costs of a renewable energy grid.
As for nuclear power, Jenkins’ most pessimistic assumption is that nuclear power costs $7,000 per kilowatt. That is actually overly optimistic. Lazard currently estimates that nuclear power costs between $6,500 and $12,250 per kilowatt. In 2016, estimates were at $5,400–8,200 for nuclear ($8,650 for new US nuclear). This means that nuclear power actually got more expensive. Jenkins doesn’t merely assume that nuclear will reverse this trend someday, but even in his most pessimistic scenario have capital costs that would be considered at the low end of the spectrum today.
To sum it up, Jenkins makes overly optimistic cost assumptions even for his “conservative” scenario regarding nuclear. And he makes overly pessimistic assumptions even for his “low” scenario regarding solar power. So he basically compares an optimistic projection of nuclear power costs to a pessimistic projection of solar power costs and finds that nuclear power is cheaper.
Now that we have looked into some anti-renewable energy propaganda studies, we can spot a set of strategies that is used by anti-renewable propagandists to discredit renewable energy.
Even pro-nuclear propagandists are very well aware of the ability to store large amounts of electricity using power-to-gas — they simply ignore it. You find Jenkins, Thernstrom, and Sepulveda mentioning that technology, but then simply go on by only calculating the costs of other, less optimal storage technologies. Sepulveda doesn’t give a reason at all for ignoring power-to-gas, Jenkins and Thernstrom dismiss scenarios that rely on power-to-gas, arguing that it “remains unproven at such large scales,” without explaining why power-to-gas, even though it is proven to work, all of a sudden would stop working if a large number of power-to-gas facilities were built.
Insisting on an inadequate storage strategy to store large amounts of energy, such as insisting on lithium-ion batteries for that task is one way to artificially inflate the costs of going renewable.
Overestimate storage needs
The study Geophysical limits talks about 12 hours of lithium-ion or pumped hydro storage needs for the USA. Wood McKenzie all of a sudden estimates 24 hours of lithium-ion storage needs for the USA, Hans-Werner Sinn estimates 16 TWh of pumped-hydro storage (more than 10 days worth of storage) for Germany, and the Clean Air Task force estimates 36.3 TWh of lithium-ion battery storage needs for California, around 46 days worth of energy storage. While the storage estimates for 12 hours of lithium-ion battery storage are already hard to justify (as there is power-to-gas as an alternative), it is quite obvious that arguing that pumped hydro or lithium-ion storage must store more than a week’s worth of electricity consumption is nonsense and designed to artificially inflate the cost estimates of a 100 percent renewable grid. This works by using the next strategy:
The Clean Air Task Force and Hans-Werner Sinn used the strategy of simply not allowing any curtailment of renewable energy at all. This, of course, inflates the cost of storage enormously. If you do allow curtailment, you can build more wind and solar power plants than usually needed — so you have enough solar and wind power even in times of less wind or sunshine, therefore reducing storage needs. For example, to get to 90 percent solar/wind power in Germany without curtailment, you would need more than 16 TWh of storage. If you accept around 22 percent curtailment, storage needs are reduced from more than 16 TWh to 1.1 TWh.
Overestimate grid expansion needs
Another way of artificially inflating cost estimates for renewable energy is to vastly overestimate the needs of grid expansion. The NREL’s estimate is a grid expansion from 85,000 gigawatt-miles to around 116,000 gigawatt-miles for 77 percent solar and wind power. So even if we calculate that for 100 percent solar and wind power, a further expansion to 125,000 gigawatt-miles might be necessary, the costs remain moderate. 1 mile is roughly 1.61 kilometers. At $1 million per gigawatt-kilometer, therefore, it would cost around $65 billion to expand the grid to 125,000 gigawatt-miles. This puts into perspective the vastly overblown grid expansion estimates by Sepulveda (252,000 gigawatt-miles or 408,000 gigawatt-kilometers at a cost of around $410 billion) and Wood McKenzie (200,000 miles of new HVT at a cost of around $700 billion).
Ignore or underestimate progress
A review of “recent literature” by Jenkins and Thernstrom in 2017 found that getting to near-zero emissions would cost significantly more than including technologies like nuclear power and CCS. One of the studies cited by Jenkins and Thernstrom is a study by Brick and Thernstrom from 2015. This study claims to “test the outer bounds of” future scenarios, assuming rapid and significant cost declines for wind and solar: Capital costs of $1000 per kilowatt and increased costs for nuclear ($6500 per kilowatt).
“In November 2018, however, Lazard considered $6500 per kilowatt the lowest end of the price spectrum for nuclear power, whereas the highest end of the spectrum was $12,250 per kilowatt. At the same time, wind and solar were estimated to cost between $950 and $1250 per kW (solar) and between $1150 and $1550 per kW (wind). Thus, what was considered “rapid and significant cost declines” in 2015, in 2018 was already within reach.