DEBATE OVER CARBON TAX VERSUS CAP AND TRADE IN WASHINGTON STATE

 

PHOTO PROVIDED BY NOW SOLAR

 

John Upton

 

Thursday, April 28, 2016 - 12:50am
VIA https://www.greenbiz.com 

As governments worldwide begin imposing fees on pollution to try to protect the climate, a debate over dueling approaches — one that long has been restricted to conferences and academia — is becoming prominent in Washington state.

Washington voters will decide in November whether to introduce a carbon tax on fossil fuels and electricity from coal and natural gas, with the goal of slowing global warming while reducing taxes on sales and manufacturing and keeping total tax revenue flat overall.

If Initiative 732 (PDF) passes, the Evergreen State would buck a national trend in which other states have been adopting a different system for carbon pricing — that of cap-and-trade, in which pollution levels are capped and allowances to release pollution are sold and traded.

"Some folks on our executive committee and in our grassroots base have a strong preference for a carbon tax," said Yoram Bauman, an economist and comic involved with Carbon Washington, a group that drafted the initiative and gathered signatures.

Carbon pricing is popular among economists and climate experts because it can account for some of the hidden costs of climate change by taxing fossil fuels, which raises prices and reduces demand. That helps solar, wind and other climate-protecting alternatives compete on price.

"The differences between carbon taxes and cap-and-trade programs are dwarfed by the similarities between them."

Worldwide, carbon pricing is being adopted rapidly as countries and states work to slow global warming. China plans to roll out a nationwide program next year, joining the European Union, Kazakhstan, California and other governments in putting a price on carbon.

The World Bank and International Monetary Fund were campaigning in support of carbon pricing ahead of the signing last week of the United Nations’ climate treaty, finalized in Paris in December.
Some experts prefer a carbon tax over cap-and-trade, arguing that it’s more efficient and less complicated. Others prefer cap-and-trade, arguing that the approach provides governments with greater control over the amount of pollution that’s released each year.

Bauman said a carbon tax is "simple and transparent," and he pointed out that neighboring British Columbia already has a carbon tax in place. "The choice of a carbon tax for I-732 came from some issues that are pretty specific to Washington state."

(Carbon pricing programs worldwide in 2015. Credit: World Resources Institute, "Putting a Price on Carbon: A Handbook for U.S. Policymakers.")

 

The debate has spilled into the Democratic primary race, with Bernie Sanders pushing for a carbon tax. In 2007, Hillary Clinton said she opposed a carbon tax — but only because she favored cap-and-trade.

The ballot initiative is the latest effort to establish a system in Washington that prices carbon pollution. Cap-and-trade legislation by Gov. Jay Inslee was rejected last year by lawmakers, and his administration is trying to cap carbon pollution using regulatory powers.

"The differences between carbon taxes and cap-and-trade programs are dwarfed by the similarities between them," said Noah Kaufman, a climate economist at the nonprofit World Resources Institute. "A lot of the differences that you hear talked about are not really fundamental differences between the policies, but what to do with the revenue."

The Washington ballot measure was crafted to be revenue neutral for the state, helping to curb pollution while reducing other taxes. A government analysis indicated those cuts substantially could reduce state revenue overall, although backers of the proposal disagree with the finding. Major winners would be low-income families, which would receive $1,500 tax rebates.

Carbon Washington is facing opposition to its ballot initiatives from corporations that use and produce energy.

"We don’t think a price on carbon is necessary," said Brandon Houskeeper, who oversees government affairs at the Association of Washington Businesses. "We think it’s the wrong approach."
The planned revenue neutrality of the measure also has sparked opposition from groups that are fighting for a system that sets aside funds for environmental initiatives.

California, European nations and some other governments earmark large chunks of revenues from cap-and-trade programs to be spent on efforts to promote clean energy and reduce pollution impacts in poor communities.

Washington’s carbon tax ballot initiative "doesn’t have a huge united coalition behind it," said Kristin Eberhard, a researcher who tracks carbon pricing for the Sightline Institute, a think tank based in Seattle.

Climate Solutions, a nonprofit in the Pacific Northwest, said it can't support but won't oppose I-732, preferring to continue to push for adoption of an alternative carbon pricing program — one that would provide funding for environmental initiatives in Washington.

"We need a more comprehensive solution," said Vlad Gutman, director of Climate Solutions’ Washington office. "We need to drive investments to clean energy."

John Upton

Senior Science Writer

Climate Central

ON

King County Judge Makes Historic Ruling Against Washington State in Climate Change Case

by Sydney Brownstone • Apr 29, 2016 at 12:30 pm
VIA https://www.thestranger.com

King County Judge Hollis Hill sided with eight kid plaintiffs arguing that the state wasn't doing enough to address climate change. SB

 

A King County Superior Court judge has reversed a ruling that gave the Washington State Department of Ecology the opportunity to decide when to cut statewide greenhouse gas emissions. Because of a lawsuit filed by eight Washington State kids, Judge Hollis Hill has ruled that the threat of climate change is so urgent that the state must be placed on a court-ordered deadline to hold polluters accountable now.

The decision was the first of its kind. Earlier this year, Judge Hill found that the state had a constitutional responsibility to protect its citizens—including the children who filed the lawsuit—but that dictating an additional greenhouse gas rule-making process wouldn't be necessary. After all, in July of last year Governor Jay Inslee had directed Ecology to come up with a rule to cut greenhouse gas emissions.
That changed when Ecology withdrew the draft rule in February of 2016 in order to take more time to confer with stakeholders. When that happened, the kids' lawyer, Andrea Rodgers, asked the judge to change the earlier ruling in favor of the state based on two criteria: one, that the state had misrepresented the facts, and two, that extraordinary circumstances deemed it necessary.
Judge Hill didn't think that Ecology committed fraud or misrepresentation by committing to a rulemaking process and then withdrawing a draft rule later. But she did agree with the kids' lawyer that climate change constituted extraordinary circumstances.

"Ecology doesn't dispute that current science establishes that rapidly increasing global warming causes an unprecedented risk to the earth, to the land, sea, and atmosphere, and all living plants and creatures," Judge Hill said. Then the judge used Ecology's own words to demonstrate the "extraordinary" circumstances, reading back a quote from 2014 warning of "serious economic and environmental disruptions."
Judge Hill continued:

The reason I'm doing this is because this is an urgent situation. (...) These children can't wait, the polar bears can't wait, the people of Bangladesh can't wait. I don't have jurisdiction over their needs in this matter, but I do have jurisdiction in this court, and for that reason I'm taking this action.

Now the state must come up with a rule to cut greenhouse gas emissions by the end of 2016. In addition, it must make recommendations to the legislature next year to update the state's greenhouse gas reduction goals based on the most current science.
In order to demonstrate how climate change posed an immediate threat to Washington citizens—and how the state had failed to protect them from it—lawyer Andrea Rodgers cited the Quinault Indian Nation's plan to relocate its ancestral village of Taholah away from the coastline because of rising sea levels. "People think that this is something that's going to happen down the road when our friends, and our family, and our people in Washington are literally being relocated," Rodgers said.

As for the judge's ruling on extraordinary circumstances, "It's not climate change that's the extraordinary circumstance, it's that this agency hasn't done what it's legally obligated to do for almost 30 years," Rodgers told me after the courtroom let out. "And [Judge Hill] recognized that a court has a responsibility to step in and protect the rights of young people that are being harmed by climate change. This is world-changing and it's amazing."
The kid plaintiffs and their friends inside the courtroom were similarly stoked.
"I think it's our biggest victory so far," 12-year-old Athena Fain said.
"I mean, [Ecology] are our 'elders,' so to speak, and they're supposed to guide us and help us, and it kind of feels like we're guiding them to help us," 14-year-old Gabe Mandel added. "So we're totally thankful that amazing Judge Hollis Hill ruled in our favor."
A spokesperson from the Department of Ecology stressed that the state was already taking climate change seriously. "We're already working on an aggressive schedule trying to put this policy in place, and we're going to stay on that schedule," Ecology spokesperson Camille St. Onge said. "It's our top priority as an agency. We understand how vital it is to protect our air, and our water, and our land for future generations."

UPDATE: Governor Jay Inslee released a statement on Judge Hollis Hill's ruling.
Below:

This case is a call to act on climate, and that call is one that has been a priority for me since taking office. Our state is helping lead the way on climate action in our country.
It appears the court is essentially reaffirming the need to do what we've already committed to doing, which is putting a policy in place by the end of the year that reduces carbon pollution in Washington state.
In a way it is gratifying that the court has also affirmed our authority to act, contrary to the assertion of those who continue to reject action on climate change and ocean acidification. Hundreds of people have participated in the creation of our state's Clean Air Rule and the draft will be out in just a few weeks. People can also view the webinar held earlier this week in which over 500 people participated.

I'm fully committed to making sure we do our part to protect our air and water for our children in the years ahead.

Cover this amount of U.S. land with solar power plants and you could power the entire United States.

Mercom Says Global Solar Installations Set To Reach 66.7 GW In 2016

Global solar installations are expected to reach 66.7 GW in 2016, thanks to strong growth in China, the US, Japan, and India, according to Mercom.



READ THE REST OF THE REPORT HERE

A Researcher Just Accidentally Developed A Battery That Could Last A Lifetime

April 22, 2016 | by Alfredo Carpineti
VIA http://www.iflscience.com

Hang on renewables this is only the beginning. We have seen great leaps in renewable production due to investment and markets. Product efficiency has grown dramatically while cost has plummeted at unprecedented rates.
The last couple of years we have witnessed this happening on the storage side as it is very apparent that if renewables wants to really be a competitive power option it needs to be available on demand. This article posted below from IFLScience! focus' on the science aspect so it will be interesting to discover what the financial feasibility reveals.


Poor battery life is the number one complaint when it comes to smartphones and laptops. As a wireless society, having to tether ourselves down to power up our gadgets seems more and more a nuisance. And while researchers are looking into wireless charging, if batteries were better we would have to worry less.

Now, a new technology promises just that. Researchers from the University of California, Irvine, have invented a nanowire-based battery that can be recharged hundreds of thousands of times, a significant leap towards a battery that doesn’t require replacing.

Nanowires possess several ideal characteristics for electric storage and transmission. They are highly conductive and thousands of times thinner than a human hair, which means they can be arranged to provide a large surface area for electron transfer. Unfortunately, nanowires are usually very fragile and don’t do well after repeated charging and discharging.


The researchers, whose findings are published in the American Chemical Society’s Energy Letters, have coated gold nanowires in manganese dioxide and cocooned them in a Plexiglas-like gel. This combination keeps all the properties of the nanowires' intact and makes them resistant to fractures.

Mya Le Thai, the lead study author, has charged and discharged the battery up to 200,000 times without breaking the nanowires and without loss of capacity.

“Mya was playing around, and she coated this whole thing with a very thin gel layer and started to cycle it,” said senior author Reginald Penner, chair of UCI’s chemistry department, in a statement. “She discovered that just by using this gel, she could cycle it hundreds of thousands of times without losing any capacity.”
“That was crazy,” he added, “because these things typically die in dramatic fashion after 5,000 or 6,000 or 7,000 cycles at most.”


The researchers believe that the combination of the PMMA (plexiglass-like) gel electrolyte and the magnesium oxide gives flexibility and structure to the nanowires, preventing cracking and thus extending their operational life.

“The coated electrode holds its shape much better, making it a more reliable option,” Thai said. “This research proves that a nanowire-based battery electrode can have a long lifetime and that we can make these kinds of batteries a reality.”



VIA http://pubs.acs.org/doi/full/10.1021/acsenergylett.6b00029

We demonstrate reversible cycle stability for up to 200 000 cycles with 94–96% average Coulombic efficiency for symmetrical δ-MnO₂ nanowire capacitors operating across a 1.2 V voltage window in a poly(methyl methacrylate) (PMMA) gel electrolyte. The nanowires investigated here have a Au@δ-MnO₂ core@shell architecture in which a central gold nanowire current collector is surrounded by an electrodeposited layer of δ-MnO₂ that has a thickness of between 143 and 300 nm. Identical capacitors operating in the absence of PMMA (propylene carbonate (PC), 1.0 M LiClO₄) show dramatically reduced cycle stabilities ranging from 2000 to 8000 cycles. In the liquid PC electrolyte, the δ-MnO₂ shell fractures, delaminates, and separates from the gold nanowire current collector. These deleterious processes are not observed in the PMMA electrolyte.





 Degradation and Failure Discovery Platform. (a) Schematic diagram showing critical dimensions of the Au@δ-MnO₂ all-nanowire capacitor investigated here. The PMMA gel layer, consisting of 20 (w/w)% PMMA in 1.0 M LiClO₄ and PC, is 180 μm in thickness. (b) Low-magnification image of a several Au@δ-MnO₂ nanowires on the capacitor surface. (c) High-magnification SEM image of the gold nanowire core of the Au@δ-MnO₂ nanowires with lateral dimensions of 35 nm (h) × 240 nm (w). (d) High-magnification SEM image of a Au@δ-MnO₂ nanowire showing the morphology of the electrodeposited δ-MnO₂ shell with a mean thickness of 124 nm.(1) (e) Photograph of the capacitor containing 750 parallel nanowire loops patterned onto a glass microscope slide.






(Below) SEM (a–d) and AFM (e–h) images of gold (a,e), and Au@δ-MnO₂ core@shell (b–d, f–h) nanowires: (a,e) gold nanowire comprising the core of Au@δ-MnO₂ core@shell nanowires. A height versus distance amplitude trace is shown below each AFM image. (b,f) Au@δ-MnO₂ core@shell nanowire prepared by electrodepositing MnO₂ onto the gold nanowire shown in (a) for 5 s. (c,g) MnO₂ deposited for 10 s. (d,h) MnO₂ deposited for 40 s. (i–k) Charge storage performance for all nanowire capacitors composed of Au@MnO₂ nanowires. All data here were acquired using the PMMA gel electrolyte except in the case of the 222 nm shell thickness, where data for the PMMA gel electrolyte and PC-only electrolyte are both shown (k). (i) Cyclic voltammograms at 100 mV/s for capacitors prepared with three MnO₂ shell thicknesses, 143, 222, and 300 nm, as indicated. (j) Galvanostatic charge/discharge curves for nanowire capacitors at 1 A/g. Total C_sp values are 19, 34, and 56 F/g for t_MnO2 values of 300, 222, and 143 nm, respectively. (k) C_sp versus scan rate for MnO₂ nanowire arrays. For the 222 nm shell thickness, data for PMMA (solid green line) and no PMMA electrolytes (dashed green line) are compared. Error bars represent ±1σ for three as-prepared capacitors at each t_MnO2.





Cycle stability of Au@δ-MnO₂ core@shell nanowire capacitors. (a,b) C_sp versus cycles for MnO₂ shell thicknesses as indicated. Also plotted (top) is the Coulombic efficiency for the 222 nm MnO₂ shell thickness. Other shell thicknesses were virtually identical. (b) Detail showing the first 20 000 cycles in (a). (c) CVs at 100 mV/s for the 222 nm MnO₂ shell thickness acquired for cycle 1 and cycle 100 000, as indicated. (d) C_sp versus scan rate for the 222 nm MnO₂ shell thickness, for data acquired at 6000, 40,000, 75 000, and 95 000 cycles, as indicated




Figure 4. SEM analysis of Au@δ-MnO₂ nanowires before and after cycling. (a–d) SEMs at low (a,c) and higher (b,d) magnification show two identical, as-prepared Au@δ-MnO₂ nanowires with shells of thickness 220 nm. (e,f) SEMs of the same nanowire shown in (a,b) after 4000 charge/discharge cycles. The short-range loss of MnO₂, from 100 to 500 nm domains, is readily apparent in these images (green arrows). (g,h) SEMs of the same nanowire shown in (c,d) after 100 000 charge/discharge cycles. In contrast to (e,f), using the PMMA gel electrolyte, no shell loss is observed in this case. SEM analysis of Au@δ-MnO₂ nanowires before and after cycling. In PC without PMMA, short-range loss of MnO₂ (e,f) precedes long-range loss of the MnO₂ shell over a length scale of microns. SEM images of a single nanowire loop of a Au@δ-MnO₂ core@shell structure without PMMA (i) and with PMMA (j) document the loss of the MnO₂ shell (green arrows) in the absence of the PMMA





Scheme 1. (a) Illustration of the Two-Stage Progression of Degradation for Au@δ-MnO₂ Nanowires in PC Electrolyte without PMMA gel^a and (b) Addition of PMMA to the PC Electrolyte Forestalling Both of These Degradation Modes

Sorry Tri-Cities Solar Incentive ends.

Benton PUD, City of Richland, Benton REA and Franklin PUD have filled up their allotted amount for the Washington Solar Production incentive. The current law reads that the utilities can only get 0.05% of their power from solar by using the incentive. The incentive allowed solar customers to get paid up to $5,000 a year until 2020. The program lasts until 2020 but most of the utilities in Washington have capped out the 0.05% allowed. There was a bill earlier this year to change the minimum amount of 0.05% but it did not pass. If you use all Washington product they will pay you up to $0.54 kWh up to $5,000 a year until 2020. The good news is that we can still show a 5 year or less return on investment for commercial systems as we are not subject to the made in Washington clause and can pass these huge savings on to you. When combined with the Federal business solar incentives the ROI is very attractive. Customers can still benefit from net metering!!!

Richland Washington Ends Solar Incentive

The City of Richland has filled up its allotted amount for the Washington Solar Production incentive. The current law reads that the utilities can only get 0.05% of their power from solar. Richland is the second utility in our area (Benton REA was the first) that has filled up the very popular Washington Solar Production Incentive. The incentive allowed solar customers to get paid up to $5,000 a year until 2020. The program lasts until 2020 but most of the utilities in Washington have capped out the 0.05% allowed. There was a bill earlier this year to change the minimum amount of 0.05% but it did not pass. If you use all Washington product they will pay you up to $0.54 kWh up to $5,000 a year until 2020. Franklin PUD (Pasco) and Benton PUD Kennewick) still have availability so call us and reserve your system today (509) 412-1766. We apologize to all our Richland customers that were wanting to use the Washington solar incentive to pay down their systems. The good news is that we can still show a 5 year or less return on investment for commercial systems as we are not subject to the made in Washington clause and can pass these huge savings on to you. When combined with the Federal business solar incentives the ROI is very attractive.

'Revolutionary' Solar Cell Hits 100% Efficiency

Holy grail of photovoltaics found with novel compound semiconductor material dubbed 'liquid sunshine'
01 Apr 2016.  VIA http://optics.org/
by Pini Salvador.

by Pini Salvodor
Researchers have discovered what appears to be the “holy grail” of photovoltaics – a new semiconductor material capable of converting the entire solar spectrum into "green" electrical power with 100% efficiency.
The team, a multinational collaboration, reported its findings this morning in the Journal of Solar Materials. In the paper, they describe their accidental discovery of a completely new semiconductor material based on a combination of the noble gas argon and the semiconducting non-metal element selenium - caused when an argon gas cylinder leaked over a large bowl of brazil nuts whose selenium content was being analyzed by food researchers.
“It’s unbelievable,” said principal investigator Olaf Pirlo. “This is the renewable energy breakthrough that the whole world has been hoping for. The efficiency of our ArSe-based solar cells outperforms that of every other known photovoltaic material by a factor of at least two.”
The astonishing efficiency performance has since been confirmed at the UK’s National Sunshine Laboratory, which is based in Manchester.
Sunshine indoors
Up until now, the highest recorded efficiency from a research-grade solar cell stood at 46 per cent, set in late 2014 by a team from Soitec alongside the Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg.
But the new cell is set to head straight to the top of the famous US National Renewable Energy Laboratory (NREL) chart of high-performance devices, and in the longer term the disruptive technology promises to turn the solar power industry upside down – if it can be produced cheaply and in commercial volumes.
Pirlo is extremely confident about that, partly because the new material can simply be sprayed or painted onto any suitable substrate material. The unusual combination of chemical elements means that ArSe exists in a convenient liquid form at room temperature, leading Pirlo’s team to dub the semiconductor “liquid sunshine”.
And because the material is particularly good at converting warm-white light into electricity, it will also suit interior applications, effectively bringing - in Pirlo's words - "sunshine indoors".
He is currently in negotiations to secure the funding needed to construct a fabrication facility to make large solar panels based on the material, with volume production tentatively scheduled to start next April.
At that point Pirlo and his colleagues are planning to sell the revolutionary technology direct to customers via a web portal owned and operated by their spin-off company "MyArSe".

Warning of SunEdison bankruptcy risk issued by yieldco subsidiary

By Mark Osborne

Mar 29, 2016 12:53 PM BST

Stocks: SUNE, GLBL

Embattled renewables firm SunEdison is said to be close to seeking bankruptcy protection, according to one of two subsidiary yieldcos, Terraform Global in an SEC filing.
Terraform Global said in financial statement that parent company SunEdison, was at a "substantial risk" due to its "liquidity difficulties" and "will soon seek bankruptcy protection".
TerraForm Global drew attention to SunEdison’s financial position due to the delayed filing of SunEdison’s fourth quarter and full-year 2015 financial results, which could also trigger clauses for bondholders to seek the return of funds.
The delays in filing its financial reports also affects the ability of the yieldcos, due to previously stated "weakness in internal controls over financial reporting".

These $150,000 Prefab Houses Don't Need Any Energy From The Grid

Deltec's factory-built houses get their power from solar panels—and incredible gains in efficiency.


BY: Adele Peters 03.14.16 6:00 AM
VIA http://www.fastcoexist.com

When a home-building company called Deltec Homes first launched in 1968, they focused on designing houses that could survive a hurricane. Now one of their main focuses is a different challenge—how to make affordable prefab houses that don't require any electricity from the grid.
The company has been developing a line of net-zero homes for the last decade. "People 10 years ago didn't call them net-zero homes," says Steve Linton, president of Deltec. "But people were building homes that essentially produced all their own energy and asking us to play a big part in that type of project. It's sort of a long evolution for us."



At first, it was a limited experiment, but the company quickly realized that they could make an entire line of houses. "We kind of had an 'aha' moment where we said look, we've gotten really good at designing homes this way," he says. "We really can drive down the energy consumption piece so that the amount of renewable energy required is really affordable—so why not apply it to other architecture?"
The company currently makes nine different models of net-zero houses, each designed to cut out two-thirds of the energy used in a typical house of the same size. The rest is powered by rooftop solar.
"It starts the energy conservation," Linton says. "We know that ultimately it's better to save a kilowatt hour of electricity than to produce an extra one." By making the walls in a factory, for example, it's possible to include gaskets that make them more airtight than if they were built piece by piece on site. The company also works with clients to plan a design based on their land—how the sun can warm and light the house, and how trees can keep it cool. Windows are chosen to either let in heat from the sun or keep it out, based on the location.



The company also helps save energy by encouraging people to buy smaller homes. "The average home size today in America is twice what it was in the 1950s," he says. "It's gone from a 1,000-square-foot home average to over a 2,500-square-foot home average. That, at the end of the day, is really driving energy consumption. . . . We've got to find a way to start changing that dynamic for new homes if we're really going to have an impact on the overall sustainability of homes."
Though the line includes larger houses for larger families—up to around 2,100 square feet—it also sells models that are only 800 square feet.
By making the pieces of the house in a factory, it's possible to completely build the exterior in a few days, as opposed to weeks or months for a typical house. That means the house is weatherproof more quickly, and ultimately can last longer. Prefab materials also help keep the cost down; the shell of some of the basic homes starts at around $66,000 (building out the inside, with local contractors, brings the cost of the cheapest model up to at least $145,000).



"You know when you talked to people 10 or 20 years ago about a modular home, a panelized home, a prefab home, they generally saw that as a lower product than a site-built home," says Linton. "But I think in the last decade or so there's really been a paradigm shift in people's perception of that—where they realize they're getting so much more now than they can get by doing it the old way. I think about all of the products that we use in our daily lives, and really houses are the last product that isn't, for the most part, built in an advanced manufacturing facility."
After launching two additional sizes of one of their houses a month ago, Deltec plans to add another two or three new styles of homes later this year. "We're continually innovating and adding more," Linton says.

Why this new solar market could be set to explode

VIA https://www.washingtonpost.com
By one of my favorite reporters: Chris Mooney
March 24 at 12:29 PM

A rooftop solar power project is shown in 2014 in Berlin-Lichtenberg’s “Yellow Quarter” district in Germany. Hundreds of tenants are supplied with power from the roof. (Jorg Carstensen/AFP/Getty Images)

Right now, there’s an odd thing about solar in the United States (and elsewhere). It’s either really big — at the scale of massive solar farms with the capacity to generate tens or hundreds of millions of watts of electricity — or pretty small: on your rooftop, with maybe as little as 5 kilowatts, or thousand watts, of capacity.

Solar has been growing extremely fast in these existing markets. But more and more, analysts say, there’s a middle-range market whose large potential is just becoming clear. It’s bigger than individual rooftop installations but smaller than vast solar farms. And it’s for a much broader and diverse range of people than fairly wealthy, suburban homeowners.

It’s called community or “shared” solar, meaning that multiple people get electricity from a mid-sized solar array on the top of, say, a condo building, or in a lot centered in a community, or perhaps an array or resource designated by their power company. This means people living in more densely populated cities, who may not own the roofs over their heads or who may not have the best credit, could also participate in the solar wave — without having to purchase or finance panels themselves.
 As of 2015, only a tiny sliver of all solar capacity in the United States fit into this category. But according to a new report from the energy think tank the Rocky Mountain Institute, the potential for community solar to expand is vast. The group said that as much as 30 gigawatts (or billion watts) of solar capacity, at the extreme upper end, could be added in this space by the year 2020, which would more than double all currently installed solar capacity in the United States.
Granted, that also requires a redefinition of what community solar is — the group calls it “community-scale” solar to denote mid-sized arrays, whether owned by a group of individuals or by a power company.

By this definition, “community-scale solar reaches millions of U.S. customers that so far rooftop solar has not or cannot,” notes the report. It found that almost half of all U.S. homes and businesses cannot have solar even if residents want it “because they rent their home, live in dwellings such as a multi-unit apartment building or high-rise condo, or have a roof unsuitable for solar.”

Hence the size of this market: The Rocky Mountain Institute says it is larger than prior estimates for three main reasons. One, solar tax credits have again been extended; second, the price of the technology keeps falling; and third, the institute defines the market more broadly, to include offerings by different types of power companies, including rural electric cooperatives and municipal utilities.

“Community-scale solar is at a sweet spot between utility-scale and behind-the-meter solar,” says the document. “It is neither too big nor too small; it is just the right size to capture community and distributed energy benefits on the one hand and utility-scale solar’s economies of scale on the other.”
Another report on the subject, released by the Deloitte Center for Energy Solutions, details why it is likely going to be good business for more utility companies of all types — ranging from large, investor owned utilities to rural electric cooperatives — to offer more shared solar programs to customers. Like the Rocky Mountain Institute, then, Deloitte is focused in particular on the kind of community or at least community-scale solar that would be offered by power companies, rather than set up by a group of individuals (like, say, a condo building).

This follows on research published last year, which suggested that utility companies are getting quite interested in these types of programs — in part because they could allow them to give their customers a taste of solar without the risk of losing some of their business because they start generating their own rooftop electricity.

The Deloitte report suggests interesting ways that power companies can integrate shared solar into their businesses. For instance, power companies can bundle together the option of joining a shared solar plan with other services — such as the installation of new, more efficient electric water heaters. Then, solar could be used to power those heaters at night, in effect “storing” that energy in the form of hot water for use during the day. This could reduce overall energy use during peak afternoon and early evening hours, when electricity is most expensive on the grid. The Deloitte report notes that at least one utility, Steele-Waseca Cooperative Electric in Minnesota, is doing just that.

In another example, if a utility installs an array of solar panels and lets customers opt to receive part of their electricity from them, the Deloitte report notes that these panels could be faced west to capture sunlight late in the day. Again, that’s the period of high demand and so could offset the utility’s costs.

“As innovation takes its course, shared solar business models are continuing to evolve, and the opportunity is becoming more evident,” the report observes.
Granted, community solar also needs policy to help it along. Some states have passed laws allowing for “virtual net metering,” an extension of standard “net metering,” in which rooftop solar owners get credited for extra power that they generate and send back to the grid, and thus lower their utility bills.  Virtual net metering goes a step further by allowing the participant in a community solar arrangement to do the same, even if he or she does not individually own the actual solar panels in question.

This can make community solar more financially advantageous to those who participate. But according to the Rocky Mountain Institute, while changes to net metering policies can greatly alter the financial picture for individual rooftop solar owners, it’s not as crucial with all forms of community solar. “Unlike most behind-the-meter solar, community-scale solar can be cost-competitive even in the absence of net metering,” the report says.

Indeed, if it’s utilities offering community-scale solar programs, then it’s not at all clear that virtual net metering will be involved. Net metering itself has been a key point of contention between power companies and rooftop solar users: According to Varun Rai, a professor at the University of Texas who co-authored the aforementioned study on utility interest in community solar last year, utilities won’t want to go there.

“For all practical purposes, the only difference between virtual net metering and net metering is, you don’t have the system on your roof,” Rai said last year. “But for the utility, you are exactly the same on your bill.”

So in sum, solar is certainly booming at the moment — but it may not yet be anywhere near its full potential.