Green Energy

Today, the numbers on renewable energy output in Denmark in 2018 are out. The organization Danish Energy (Dansk Energi) reports that the share of wind energy was lower than 2017, but the share of solar energy was a record high, with 2.8% of the country’s total electricity consumption covered by solar photovoltaics.

It was a hot and sunny summer last year. May, June, and July had 40% more sunlight than the same months the year before. 2018 in total had 25% more sunlight than 2017.

It’s not that the share of wind was bad. In fact, despite the calm summer (19% less wind in June!) wind power covered 40.8% of total electricity consumption. That’s only just about 3% lower than the record year 2017.

When you add it all up, including trade with neighboring countries, a whopping 68% of the Danish electricity supply originated from renewables.

Kristine Grunnet, Chief consultant at Danish Energy, says that the result underlines the fact that land-based wind turbines and photovoltaics, which already deliver more than 30% of the country’s electricity consumption, are the two cheapest green energy sources today — despite the large price decreases in offshore wind. “My expectation is that land-based renewable energy will soon be commissioned without incentives. It has developed into a profitable investment that has a large and ever-increasing role in the green transition,” says Grunnet.

The world’s first building-integrated field test of a one square meter perovskite solar panel, made by Saule Technologies, has just begun on Sanska’s Spark office in Warsaw, with a projected 5 cent per kilowatt-hour levelized cost of energy, according to Saule.

The pilot test panel is 1.3 by 0.9 meters, containing 52 photovoltaic free-form halide perovskite solar modules made by ink jet printing. Commercial scale production is hoped for by 2021.

The cost of the panel is projected at $58 per square meter, with an expected 10% efficiency, according to a May interview with Agata Kukwa, the spokesperson for Warsaw-based Saule, by San Francisco-Based Clean Tech Group.

Perovskite solar cells can be made flexible, ultra thin, lightweight and semitransparent, and the Saule modules also present aging stability and water resistance that will enable their use by the commercial construction industry. CleanTechnica has followed Perovskite manufacturing advances closely; see the December 27th story.

Perovskites are a class of materials that share a similar structure, which display a myriad of properties like superconductivity, magnetoresistance, and more, according to Perovskite-Info.com. These easily synthesized materials are considered the future of solar cells, as their distinctive structure makes them perfect for enabling low-cost, efficient photovoltaics. They are also predicted to play a role in next-gen electric vehicle batteries, sensors, lasers and much more, the group says.

Saule is working with the Warsaw-based Ergis Group, a rigid plastics film producer, on the encapsulation of the cells.

“The first pilot production facility is scheduled to be launched at the end of 2019 ,which would allow for the fabrication of large perovskite PV modules on an industrial scale. At the same time, we will be working on process optimization in order to improve the operational parameters of the fabricated panels,” said Konrad Wojciechowski, CSO and Project Manager at Saule, in a December statement.

The company has several research grants worth more than EUR 20 million, including funds from the Polish National Centre for Research and Development. The company also has signed an investment agreement with Hideo Sawada, a Japanese investment company.

Contractor Sanska has exclusive rights to use Saule Technologies’ solar cell solutions through a license-based agreement for installations on building façades and noise barriers across all Skanska markets worldwide.

Saule has conducted research on perovskite applications in solar energy harvesting and optoelectronics with universities in the UK, Israel, Germany, Italy and Spain. The company is a member of a three-year European Union-funded project, ESPResSo, for the Efficient Structures and Processes for Reliable Perovskite Solar Modules, that has gathered leaders in perovskite PV technology to revolutionize Europe’s photovoltaics industry.

The group has a goal of bring the cell performance close to its theoretical limit by demonstrating cell efficiency of more than 24% on a 1 centimeter-square cell, with less than 10% degradation in cell efficiency following thermal stress at 85°C and at 85% Relative Humidity (RH) for over 1,000 hours. The group also is working on scale up activities utilizing solution-processed slot-die coating, and laser processing to attempt to deliver modules with more than 17% efficiency, showing over 20 year reliability performance to meet international standards, according to the Dutch R&D group IMEC.

The ESPResSo Group includes: Ecole Polytechnique Federale de Lausanne, Switzerland and Consiglio Nazionale delle Ricerche, Italy; perovskite solar cell scale-up and industrialization members imec, Belgium, Universita degli Studi di Roma Tor Vergata, Italy and Fraunhofer Institute for Solar Energy Systems ISE, Germany; and experts in sustainability and renewable energies CSGI (Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase), Italy and University of Cyprus, Cyprus. Members representing materials development include Dycotec Materials LTD, United Kingdom, Dyenamo AB, Sweden and Corning SAS, France; equipment manufacturer, M-Solv LTD, United Kingdom; and building-integrated photovoltaics developer, Onyx Solar Energy SL, of Spain.

A perovskite solar cell is a type of solar cell which includes a perovskite structured compound, most commonly a hybrid organic-inorganic lead or tin halide-based material, as the light-harvesting active layer, explains Perovskite-Info. Perovskite materials such as methylammonium lead halides are cheap to produce and relatively simple to manufacture. Perovskites possess intrinsic properties like broad absorption spectrum, fast charge separation, long transport distance of electrons and holes, long carrier separation lifetime, and more, that make them very promising materials for solid-state solar cells, the group says.

The production of solar power grew by 50% in the Netherlands last year. Wind power production remained the same.

The share of renewables in the country’s electricity consumption rose from 15% to 17% compared to the year before.

The share of renewables in total energy consumption rose from 6.6% to 7.3%.

These figures were released by an official website (www.energieopwek.nl) from the Dutch government tracking renewable energy production in the Netherlands on a daily basis.

Solar PV production in the Netherlands grew from 2.2 TWh to 3.47 TWh in 2018, about 3% of total electricity consumption.

Wind turbines generated some 10.8 TWh of electricity, of which 6.9 TWh came from land, 3.9 TWh from offshore. Wind power, which covered almost 9% of Dutch electricity use, showed no growth because no net capacity was added. The Netherlands has a very ambitious offshore wind program, with a target of 49 TWh in 2030, but this won’t kick in until after 2020.

The production of electricity from biomass grew from 4.7 TWh to 5.8 TWh last year.

The strong growth in solar PV production was mostly due to large-scale projects, Dutch energy website Energeia (paywall) reports. Solar PV capacity of large-scale projects, registered with Certiq, a state-owned company which issues Guarantees of Origin for renewable energy production, doubled to 1,523 MW in 2018.

Total solar PV capacity in the Netherlands grew by 50% to some 4.3–4.5 GW, according to solar specialist Peter Segaar, quoted by Energeia. Households do not register their panels with Certiq, since they have no interest in acquiring Guarantees of Origin. Residential solar PV rose from approximately 2 to 3 GW, Segaar estimates. He notes that the share of large-scale projects in the Dutch market grew from around a quarter to around a third in 2018.

An important reason why solar has grown faster than onshore wind is the way the Dutch support scheme (called SDE+) works. It is based on tenders which award subsidies to the lowest-cost bidders as measured against CO2 reduction. Solar PV projects have been overwhelmingly winning the tenders.

The good news is that many more large-scale solar PV projects are in the pipeline. More than 6.5 GW of projects that have been awarded a subsidy over the last few years have not been built yet. Most of these projects are still expected to be realized. And this does not include the projects that have participated in the latest SDE+ tender in the second half of 2018. In 2019, two more rounds of SDE+ tenders will follow.

At the end of 2018, California gave final approval for new building codes that will require every new home built in the state to come equipped with rooftop solar, or source power from a community solar array–starting in 2020. From a sustainability policy perspective, this is a huge step forward. “It’s definitely a bold move,” says Kelly Knutsen, director of technology advancement for the California Solar and Storage Association (CalSSA), which pushed for the mandate to pass. California is the first state in the country to adopt such a mandate, and it will apply to the approximately 80,000 new homes built in the state every year. The code also requires new construction to have more rigorous efficiency measures–like thicker insulation and tighter sealing doors–and encourages building developers and solar providers to add onsite battery storage and solar-powered water-heating systems alongside the rooftop arrays.

Some critical energy experts point out that because residences fall far below other sectors like transportation or agriculture in terms of emissions, mandating that homes go all-in on solar won’t do much to help the state reach its goal of lowering emissions by 40% by 2030. But the hyperfocus on emissions statistics misses the implication of this policy. It demonstrates that political will for a change of this scale is possible (albeit in climate policy-friendly California)–and that we can make swift and necessary advancements in both the residential construction and solar industries.

For housing developers, rooftop solar (or in shady areas where rooftop arrays are not viable, connection to a community solar farm) now must become another item on the checklist for building homes, like safe electrical wiring or a kitchen sink. To make this happen, the connections between the building industry and the solar sector will have to tighten. Ed Fenster, cofounder of the solar company Sunrun, says his business is already working with five of the top 10 residential developers in the state on putting solar on new homes set to go to market in 2020.

To comply with the mandate, developers now must absorb the cost of sourcing and installing a solar array on a home, which averages out to around $9,500 per home. Homeowners who elect to purchase the solar array along with their home will have to absorb that cost in the form of slightly higher mortgages (which has been a point of contention in a state already grappling with extremely high housing costs). But Knutsen says that over the course of 30 years, homeowners can expect to save $19,000 in energy and maintenance costs. Put differently, a solar array will add around $40 to a monthly mortgage but save a homeowner around $80 in the same month on heating, cooling, and lighting–netting them a monthly savings of $40.
Adjusting to this new way of calculating costs will be a process for people looking to buy homes in California, Fenster says, but it’s not the only option for prospective homeowners to comply with the mandate. The California code also allows new homeowners to opt to lease their rooftop solar array from the solar provider. Sunrun, for instance, specializes in solar leasing plans under which the company retains ownership and control of the solar array, but charges residents a small fee (around $100 per month, depending on the size and type of panels) to use it. Leasing, Fenster says, is a way to keep housing affordability (to the extent that it exists in California) in sight as the mandate rolls out. Making the various options clear to homeowners upon purchasing–and forging connections with solar operators–will be a point of focus for residential developers in the next year.

Lennar, a residential developer based in California but with projects across the country, already has a formula down. In 2012, Lennar built out a solar subsidiary, SunStreet, which specializes in integrating solar into the home construction process. Rather than retrofitting a solar array onto a roof, which entails an installation and wiring process, SunStreet builds the array into the roof and connects it to the electrical system as the construction is under way. This model, Knutsen says, will be something for builders and solar providers alike to look to as they adapt. David Kaiserman, SunStreet founder and Lennar president, says that his ventures are planning to offer guidance to other developers and solar providers looking to streamline solar integrations going forward.

For both the building and solar industries, this will be a significant change. Of the 120,000 residential solar installs that happen every year in California, 105,000 are retrofits on existing homes, and only 15,000 built along with new homes. The mandate will raise the number of new-home solar installations by 65,000. Solar companies are expert, now, at developing and marketing portable arrays that can be added onto rooftops. But Knutsen says the spike in demand for solar on new homes will likely force a change in their business model to a more integrated approach, like SunStreet’s. This should also pique the interest of developers, who will likely gravitate toward this approach as a way to speed construction. If solar can be built along with the house, rather than installed only after it’s completed, the overall construction time will remain fairly quick.

But there are still plenty of homes that need retrofitting as well. Fenster believes that solar providers like his company, Sunrun, should be preparing for an influx of demand. “The benefit of this mandate is the normalization that solar on every home creates,” Fenster says. “The effort to acquire a new customer often declines as the number of homes with solar in a given area rises because you’re not asking someone to be the first zip code to do something unfamiliar.” Fenster predicts that the rooftop solar mandate will continue to drive demand for both solar and onsite battery storage, and set a higher threshold for energy efficiency in the state. “Just as when you pick up a new iPhone, you can’t bear to use the old one anymore, now all the new homes will have solar, and people will feel the same desire to upgrade,” he says.

Hawaiian electric utilities have been forcefully de-linking residential rooftop solar generators at peak hours for several years, but the installation-discouraging practice may fade as refocused utility-scale solar+storage contracts come into effect. Beyond Hawaii, these new contract types, which shift curtailment risk away from the solar owner, also may help California avoid an increase in the curtailment of solar flowing onto its grid.

The issue is that the Hawaiian grid was not ready for the massive Hawaiian solar installation wave that now totals over 11% of the entire state electricity demand and about 57% of the demand by the main island of Hawaii. Since the excess rooftop solar energy can cause grid management problems, including excessively high voltage levels, Hawaii Electric, for example, has been requiring a utility-operated shut-off for home solar energy exports to the grid since 2015.

A 2015 Hawaii utility report estimates that “curtailment levels on Oahu may be at 10 percent (of a given generator’s output potential) or greater, and 20 percent possibly up to as much as 50 percent on Maui and Hawai’i Island.” These double digit levels should drop to single-digit levels in the future as smarter solar gear is installed by both utilities and solar owners.

The new contract form will first be applied to several utility-scale solar+storage projects under review by the Public Utilities Commission (PUC) of Hawaii, in which the power purchase agreement is no longer based primarily on the energy delivered, but rather on the amount available, as defined by the net energy potential and solar facility availability.

This shift in PPA terms means that a prospective developer and solar plant owner do not need to shoulder the potential double-digit revenue loss from curtailment of their facility during peak periods. Instead, the plant is recognized for its ability to respond to and support the grid when such services are needed. Such grid support, in turn, can help a utility avoid future wires-and-poles investments.

Eliminating this risk has helped drive down the cost of the PPA price proposals for several solar+storage plants now being reviewed by the state. GTM Research reported that “six come in at record-low prices for the state, under 10 cents per kilowatt-hour. The projects…would add 262 megawatts of solar and 1,048 MW-hours of storage distributed over three islands. Hawaiian Electric, which sought the bids, said the projects will provide power “in place of volatile prices of fossil fuels,” which it quotes at about 15 cents per kilowatt-hour, GTM says.

Will Giese, executive director at Hawaii’s Solar Energy Association, called the pricing “mind-blowing,” GTM reports. Among the bidding companies are AES, Innergex, Clearway, and 174 Power Global.

The US Solar Energy Industries Association observes that “With fantastic solar insolation and high electricity prices due to a dependence on imported energy, Hawaii is an ideal solar market. However, interconnection continues to be an issue as Hawaiian utilities have imposed restrictions to avoid solar generators’ loads on their systems.”

Hawaii’s utilities also are modifying their grid management to help avoid curtailment of solar. The Hawaiian Electric Companies — including Hawaii Electric, Maui Electric and Hawaii Electric Light— in 2017 submitted a plan, “Modernizing Hawaii’s Grid for Our Customers,” to the PUC for a comprehensive grid modernization strategy. This change would be crucial for the utilities to reach the state renewable resources target of 100% clean generation by 2045.

The PUC approved the first phase of the plan in February 2018. The estimated $86.3 million cost for the first phase, which will start this year and continue to 2023, will mean that most customers will pay less than $1 a month for the upgrades.

The plan calls for the installation of smart meters on homes and businesses that will facilitate more detailed communication about solar production, and about grid capacity and support needs. The plan also calls for more advanced and more versatile solar inverters to be used, at least on new installations.

The utilities also have worked with the US National Renewable Energy Laboratory to study ways to manage voltage and other issues that complicate utility management of the grid. NREL found that the utilities can rely on private rooftop solar to manage voltage through autonomous advanced inverter functionality. “Then, grid-edge devices such as secondary volt-ampere-reactive (VAR) controllers will be used to supplement the advanced inverter functions, NREL reports.

This voltage controlling capability also boost the utility’s ability to handle more rooftop solar at the same time. “The study concluded that deployment of secondary VAR controllers will increase the medium-voltage (MV) feeder’s solar hosting capacity from 5 MW to 7 MW, providing a 40% increase in hosting capacity,” NREL says.

NREL projects that the annual customer curtailment percentage for customers with the new volt–var and volt–watt control capabilities will be relatively low. About 87% of the customers would experience annual energy curtailment of less than 1% of generation, while 11% of customers would have curtailment between 1% and 5%, and the remaining 2% of customers would have curtailment of between 5% and 10% of total generation.

US-based wind and solar developer Apex Clean Energy has purchased 442.5 MW of solar projects across Virginia from local renewable energy developer SolUnesco.

The transaction includes the 150MW Carvers Creek, 150MW Moody Creek, 130MW Red Brick, and 12.5MW Rivanna projects. The four projects will generate enough clean electricity to power approximately 72,000 US homes. This acquisition brings Apex’s nationwide portfolio of solar projects to more than 3GW.

“Apex continuously seeks to grow our utility-scale wind and solar pipeline based on projects with the greatest potential to meet rapidly expanding market demand,” said Mark Goodwin, Apex Clean Energy president and CEO. “The projects recently acquired from SolUnesco are expertly sited, have strong landowner support, and offer substantial environmental and economic benefits. We look forward to bringing these projects online, enabling significant job creation and new revenue streams in communities across the Commonwealth of Virginia.”

In Virginia, Apex also has county permit approvals for two other clean energy projects: the 75MW Rocky Forge Wind and 80MW Dragonfly Solar.