Arizona law protects individual homeowners’ private property rights to solar access by dissolving any local covenant, restriction or condition attached to a property deed that restricts the use of solar energy. This law sustained a legal challenge in 2000. A Maricopa County Superior Court judge ruled in favor of homeowners in a lawsuit filed by their homeowners association seeking to…Read more
The Agua Caliente solar farm near Yuma features First Solar’s thin-film cadmium-telluride (CdTe) solar modules. Located 65 miles east of the city of Yuma, Arizona, this plant is one of the world’s largest operational PV power plants with 290MW (AC) connected to the electricity grid.
There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don't. The typical solar water heater is comprised of solar collectors and a well-insulated storage tank. The solar collector is a network of pipes that gathers the sun's energy, transforms its radiation into heat, and then transfers that heat to either…Read more
(Information provided by DSIRE - Last reviewed 02/19/2009) Incentive Type: Personal Tax Credit State: Federal Eligible Renewable/Other Technologies: Solar Water Heat, Photovoltaics, Wind, Fuel Cells, Geothermal Heat Pumps, Other Solar Electric Technologies Applicable Sectors: Residential Amount: 30% Maximum Incentive: Solar-electric systems placed in service before 2009: $2,000Solar-electric systems placed in service after 2008: no maximumSolar water heaters placed in service before…Read more
The idea of using the sun to meet the energy needs in our buildings has been with us since the time of the Greeks, with some of the design manifestations even evident in the prehistoric structures of Arizona and the Southwest. There is a great historic tradition for Arizona buildings that utilize our most abundant resource, and the current increases…Read more
Photo shows the situation after a battery discharge test at 300 amps was terminated on a 1530 AH IBE battery string when one post melted. During the discharge test all cell voltages are logged. The sum of the cell voltages was 2.73 volts lower than the 48-volt string voltage. This is an average of 118 mv per inter-cell connection, 5-10…Read more
1 Know Your Rights
2 Agua Caliente PV Power Plant Among World’s Largest
The REST workshop scheduled for this Wednesday (6/7/17) at 10am has been canceled. No future date has been set at this time. CANCELED - June 7, 2017, 10am: Special Open Meeting/Workshop - REST Review Workshop - Hearing Room One, 1200 W. Washington, Phoenix, AZ, 85007, Docket No. E-00000Q-16-0289
APS Residential Solar Policy Changes Coming Soon
The date is not yet set as of 7/19/17, but a major change is coming for new APS residential customers. The Corporation Commission will soon schedule hearings for the APS 2017 residential implementation plan. When the plan is approved, a cut-off date will be established after which new APS residential photovoltaic systems will no longer benefit from Net Metering. The Solar Center will publish the approved policy as soon as it is set. If your home is in APS service territory and you want the better deal, you must have filed a complete application package with APS prior to the deadline. The link below provides the current detail:
Transaction Privilege Tax (TPT) Changes Affect Solar Business and Customers
AriSEIA reported this past November that the TPT exemption covering the installation of solar energy systems would expire at the end of the year with new regulations going into effect on January 1, 2017. A bill was introduced in the last session of the Arizona Legislature to make the exception permanent, but it did not receive a hearing. Since there was no bill passed to extend the exemption, the new regulations are in effect. Below is the notice TEP sent to its contractors:
The First Regular Session of the 53rd Arizona Legislature adjourned last week and we wanted to make you aware of an important change that may affect your tax liability as a solar contractor. As of January 1, 2017, the gross proceeds of sales or gross income derived from a contract to provide and install a solar energy device are now taxable under the State of Arizona’s transaction privilege tax statute (see Arizona Revised Statutes Section 42-5075.B.13). An exemption for this activity had been enacted in 1996 with a sunset date of January 1, 2017. A legislator in UES’ service territory, Senator Sonny Borelli (R - Lake Havasu City), had introduced legislation that would have eliminated the sunset date and made the tax exemption permanent. However, the bill did not receive a hearing and this exemption is no longer effective as of January 1, 2017. Additionally, a policy rider effecting the exemption was not included in the budget signed by Governor Ducey.
From December 31, 1996 and up to January 1, 2017, the gross proceeds of sales or gross income derived from a contract to provide and install a solar energy device (commonly called Sales Tax in Arizona) were exempt. It appears that this is no longer the situation and sales of solar devices may be subject to sales tax (TPT). Thank your legislators.
Editorial Note: A review of the Arizona Revised Statutes http://www.azleg.gov/arstitle/ Title 42-5061 (M) on 6-6-2017 indicates "M. There shall be deducted from the tax base the amount received from sales of solar energy devices.....". Apparently only contracting is affected by the above TPT change. Watch this space for updates as the Arizona solar industry researches this subject.
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Sonnen has signed a contract with an Arizona homebuilder to install its energy storage systems along with rooftop solar on each residence in forthcoming developments.
This has long been a goal for the company, which aims to create a community of homeowners who produce and exchange clean energy, while performing distributed grid services. The sonnenCommunity in Germany has grown to 8,000 members and functions like its own utility. That robust vision would be hard to implement in the U.S., given the regulatory structures in place here.
Loading up a new-build housing development with storage may be the next best thing.
Including storage offsets the potential strain on the grid that comes from packing a feeder with a lot of new distributed solar. Savvy site selection can place the fleet of battery-equipped homes at locations on the grid most in need of some help.
"Your duck curve in this very particular node without storage is extreme," said Olaf Lohr, head of U.S. business development, describing a new neighborhood packed with rooftop solar. "But we add storage to it, and we actually alleviate that problem right away."
That sounds like a decentralized version of what utility Arizona Public Service has done with its most recent grid battery deployment. It placed two 2-megawatt AES storage systems at different points on a solar-heavy feeder in a valley northwest of Phoenix, in order to test how the location influences the system's ability to maintain power quality and voltage control.
That feeder serves a newly built housing community that features abundant rooftop solar, encouraged by the sunny climate and the west-facing roofs that can catch the late afternoon sun.
Sonnen has not finalized an agreement with a utility yet to make use of its forthcoming home network. Theoretically, the fleet of battery systems could deliver aggregated peak capacity, renewables integration, demand response or ancillary services. In practice, such virtual power plants are still being demonstrated in the U.S., especially when it comes to residential-sited systems. In Germany, Sonnen has already been doing it for several years.
The company wasn't ready to reveal the name of the homebuilder partner, but described it as a progressive builder that typically constructs 200 homes a year and aims for 300 in 2018. The project is expected to break ground in Q4.
Customers who move into the homes will automatically join the sonnenCommunity. What exactly that means for a U.S. customer is still being decided, but it will include assistance on one's energy bill, said Senior Vice President Blake Richetta.
"We want the peer-to-peer side to be a part of it," he said. "The challenge with the U.S. model is that, if you're in a physical community, we're not 100 percent sure how the peer-to-peer side is going to work."
This community won't be able to link up with the thousands of members in Germany that have entrusted Sonnen with managing their storage units, so the initial population will be limited. The team is hoping to figure out a special utility program for the homes to participate in grid services first, and then develop a more robust community trading system later on.
That's the reverse of how the platform developed in Germany.
"The logic behind the first-level Sonnen community [in Germany], which is pay for your grid feed-in, eliminate the utility, become the utility, and sell to some other guy -- that doesn't work in the U.S.," Richetta said. "We can't eliminate the utility and we can't facilitate that transaction in the same way, so the peer-to-peer side is harder."
The Arizona projects will provide an early case study of how a residential community interacts with the grid when it can both generate and store its own power. Whether Sonnen can earn money from the utility for creating this potential grid asset remains to be seen.
The company appears confident that the venture can work even without a grid service contract in hand.
The target audience here is the sustainably minded customer with some money to spend. Sonnen pitches itself as a product that lasts longer and provides more value over time than some competitors that focus more on a cheaper upfront battery cost (think Tesla, Richetta's former employer).
Whether or not that investment is economical for a given homeowner is hard to tell from the outside, and that may well be beside the point. Almost all installed Sonnen units in North America last fall were set on backup mode, which doesn't generate revenue for the owner but provides peace of mind in the event of a blackout.
The economics that matter most are whether the homebuilder profits from the partnership, and if the first round works well enough to lure in national homebuilders to scale the concept.
More than 1 million US homes have solar systemsinstalled on their rooftops. Batteries are set to join many of them, giving homeowners the ability to not only generate but also store their electricity on-site. And once that happens, customers can drastically reduce their reliance on the grid.
It's great news for those receiving utility bills. It's possible armageddon for utilities.
Anew studyby the consulting firm McKinseymodeled two scenarios: one in which homeowners leave the electrical grid entirely, and one in which they obtain most of their power through solar and battery storage but keep a backup connection to the grid.
Given the current costs of generating and storing power at home, even residents of sunny Arizona would not have much economic incentive to leave the electric-power system completely - full grid-defection, as McKinsey refers to it -until around 2028. But partial defection, where some homeowners generate and store 80% to 90% of their electricity on site and use the grid only as a backup, makes economic sense as early as 2020.
This scenario is already playing out in Australia and Hawaii, and has begun spreading to solar-friendly markets such as Arizona, California, Nevada, and New York. As batteries get cheaper and better, utilities are rattled at the prospect of losing a massive share of their revenue.
Aself-reinforcing cycleis at work. As consumers make their own energy, rates must increase on those left to cover the system's fixed costs. This raises rates still further, making it even more advantageous for customers to leave the grid.
Instead of adapting to this dynamic, utilities have generally sought to stifle solar with time-of-use pricing, demand charges, or cutting compensation for electricity exported back to the grid.
But as daily needs for many are supplied instead by solar and batteries, McKinsey predicts the electrical grid will be repurposed as an enormous, sophisticated backup. Utilities would step up and supply power during the few days or weeks per year when distributed systems run out of juice. Our analysis helps show the grid is very valuable as a backup investment, says Amy Wagner, a co-author of the McKinsey report.
Only, the business models of utilities are not designed for this. Their revenue typically depends on selling kilowatt hours: more electricity equals more money for utilities. Power users don't respond quickly to daily price spikes in their power bill, so ratepayers absorb electricity costs. That goes away in a world where software managing a grid connection can automatically switch to batteries to avoid high charges. A new business model is needed.
The only way to pay for the grid is as a network, said McKinsey'sDavid Frankel, a co-author of the report. "It's very counter to what the industry has seen." Instead of paying per kilowatt, he suggests, grid users could pay for access and reliability, with one fee covering the vast majority of usage. The model might resemble the fixed, monthly charges we're used to paying for cell phone data and calls.
At the moment, only a tiny fraction of utility customers have left the grid or installed batteries. But it's happening faster than was expected several years ago. Solar panels and battery prices are dropping fast - lithium-ion batteries have fallen from $1,000 to$230 per kilowatt-hour since 2010 - as massive new solar and battery factories come online in China and the US. By 2020,Greentech Media projects, homes and businesses will have more battery storage for energy (841 megawatts of capacity) than utilities themselves.
Utilities may find they need to retool their business models sooner than they think.
The critics enumerate what they view as invalid modeling tools, modeling errors, and “implausible and inadequately supported assumptions” in a projection of the midcentury U.S. energy supply that Jacobson and his coauthors published in PNAS in 2015. “The scenarios of [that paper] can, at best, be described as a poorly executed exploration of an interesting hypothesis,” write the experts, led by Christopher Clack, CEO of power-grid-modeling firm Vibrant Clean Energy.
Clack says their primary goal is accurate science, the better to equip policymakers for critical decisions: “We’re trying to be scientific about the process and honest about how difficult it could be to move forward.”
The text and statements by Clack's coauthors question Jacobson’s evaluation of competing energy technologies, and specifically his rejection of two nonrenewable energy options: fossil fuel power plants equipped to capture their own carbon dioxide pollution, and nuclear reactors.
Jacobson calls Clack's attack “the most egregious case of scientific fraud I have encountered in the literature to date.”
In fact, while both sides claim to be objectively weighing the energy options, the arguments and backgrounds of the protagonists belie well-informed affinities for various energy sources (and informed biases against others). As sociologists of science would say, their choice of data and their reading of it reflects hunches, values, and priorities.
Consider Clack’s coauthor Ken Caldeira, a climate scientist at the Carnegie Institution for Science. Caldeira's press release broadcasting their critique argues that removing carbon dioxide from the U.S. power supply is a massive job demanding the biggest tool box possible: “When you call a plumber to fix a leak, you want her to arrive with a full toolbox and not leave most of her tools at home," says Caldeira.
The same document then abandons this technology-agnostic tone to call out nuclear energy and carbon capture as technologies that “solving the climate problem will depend on.” And Caldeira has appealed for deploying a new generation of nuclear reactors, which he and other nuclear boosters such as former NASA scientist Jim Hansen say are needed because renewables “cannot scale up fast enough.”
They could be right. Then again, expert sources they cite, such as the International Energy Agency, have consistently underestimated renewable energy growth. And identical scale-up critiques have also been well argued against nuclear energy and carbon capture and storage (CCS).
Jacobson makes some powerful arguments for walking away from those technologies in his PNAS papers. Nuclear liabilities cited by Jacobson include the threat of future Fukushima-like disasters, nuclear weapons proliferation facilitated by large-scale uranium enrichment, and the financial risks such as those that recently bankrupted Westinghouse. And, as he notes in his rebuttal, the International Panel on Climate Change has determined there is “robust evidence” and “high agreement” among experts validating these nuclear risks.
Jacobson’s rejection of CCS technology, meanwhile, may provide deeper insight on what makes him a magnet for academic attacks.
The main thing that soured Jacobson on CCS was his own pioneering work on the climate change impacts of black carbon, or soot. Fossil fuel plants that capture most of their CO2 still release soot that's both a public health menace and an agent of climate change. In a 2001 paper in Nature on simulations of soot particles in the atmosphere, he controversially argued that soot in the air and on blackened snow and ice fields absorbs enough heat to make its climate impact second only to CO2. Sixteen years on, that view now enjoys strong support from the science community.
His style, however, has not necessarily made him popular among climate scientists. Drew Shindell, a climate modeler at Duke University, describes Jacobson as a brilliant scientist with an unusual go-it-alone style that alienates some researchers.
Whereas most climate models are honed by large teams, composed of hundreds of scientists, Jacobson single-handedly constructed the GATOR-GCMM climate model that underpins his work—including the 2001 Nature and 2015 PNAS reports. Shindell says other climate models are also shared more freely and subject to much more independent validation than Jacobson's. So when he claims that “his model is more complex and therefore better,” says Shindell, it “rubs people the wrong way."
To Shindell, however, Jacobson’s outspokenness and solo style do not invalidate his work. In fact, he argues that raising important questions is Jacobson’s greatest contribution: “His work does prompt people to really look closely. That’s also a service to the community.”
Could something similar be playing out now in PNAS? Power experts can bristle at outsiders who offer novel approaches to their problems. In 2004 Spectrum profiled mathematical modelers—a power engineer and a pair of plasma physicists—who were drawing heavy fire for the unorthodox prediction that big blackouts are inevitable. That trio (Ian Dobson, Benjamin Carreras, and David Newman) endured years of derision and saw their research funding pulled. They ultimately triumphed by all but predicting the Southwest blackout of 2011, a story I documented for Discover magazine last year.
Jacobson and his PNAS coauthors similarly crafted their own unorthodox energy model—LOADMATCH—which sets a bold vision. While their critics mostly model power grids, Jacobson's team used LOADMATCH to map out a 100-percent-renewable route to meeting all major energy needs in the continental United States. The model replaces fossil fuels for heating and transportation with hydrogen and electricity generated by renewables, thereby tackling nearly all greenhouse emissions from fossil fuels rather than just the 35 percent from power plants.
The weakest point in Jacobson’s 2015 paper identified by his critics is a heavy reliance on hydropower plants, which serve as his simulated power grid's backstop energy supply during long periods of weak sun and becalmed winds. This jumps out in the graph [above], which simulates total continental U.S. heat and power generation over four days in January 2055. Hydro turbines ramp up heavily each day after the sun sets, delivering as much as 1,300 gigawatts at their peak—a level that implies a 15-fold expansion in hydropower generating capacity.
Jacobson says the LOADMATCH code adds turbines to existing hydropower dams as required to prevent power outages. The reservoirs are untouched, and thus store the same amount of energy. But that energy is concentrated into those hours of the year when no other power source is available.
However, no such expansion is documented in the 2015 paper. Critic-in-chief Christopher Clack argues that it is a modeling error because, according his analysis, adding the required turbines at existing dams is not physically possible. And even if it were, he says, discharging the hydropower as described would impose unacceptable impacts on aquatic ecosystems and downstream water users. Invalidating that option, says Clack, means Jacobson’s scheme will cause blackouts: “The whole system breaks down.”
Jacobson admits the 2015 paper was “vague” on the hydropower upgrade but stands by its technical and economic viability. The environmental impacts, he says, reflect a cost that policymakers pursuing his road map would need to consider. All clean energy solutions will require trade-offs, says Jacobson, noting that the low-carbon grid projection that made Clack’s reputation, a 2016 report in Nature Climate Change, calls for a much larger build-out of unpopular powerlines.
Jacobson also has alternative sources of backup power, such as adding turbines to more rapidly convert stored heat from solar thermal power plants into electricity. "We could increase [their] discharge rate by a factor of 3.5 to obtain the same maximum discharge rate of hydro, without increasing the [solar thermal plants’] mirror sizes or storage,” he says.
If you’re wondering where battery storage figures in all of this, it is yet another option—though one that both Jacobson and Clack deemed unnecessarily costly in their respective studies. Clack’s 2016 projections relied mostly on flexible natural gas power plants rather than dams or batteries to handle residual power demand—delivering a 78 percent reduction of power sector carbon emissions from 1990 levels by 2030.
What is certain, from the darkening findings of climate science, is that climate change calls for a bold remake of the global energy system of the sort that both Clack and Jacobson have championed. Their respective visions certainly appear to have more in common than ever as the Trump administration seeks to turn back the clock on grid engineering.
The U.S. power sector is bracing for the release of a power grid study ordered by President Trump on whether renewable energy installations degrade grid reliability by undermining continuously operated “baseload” nuclear and coal power plants. U.S. Energy Secretary Rick Perry’s memo commissioning the study states as fact that “baseload power is necessary to a well-functioning electric grid.”
Last week, the Rocky Mountain Institute’s Mark Dyson and Amory Lovins called out that “curious claim,” which they say, “has been thoroughly disproven by a diverse community of utilities, system operators, economists, and other experts that moved on from this topic years ago.” What the grid needs, they write, is flexibility, not baseload power plants.
The power industry is already moving in that direction. For example, flexibility was California utility PG&E’s central argument last year when it announced plans to shut down the Diablo Canyon nuclear plant when its reactor licenses expire in 2024 and 2025. The baseload plant was ill suited, PG&E said, to help them manage the increasingly dynamic power flowing on California’s grid.
Dyson and Lovins' prescription for the power grid community, meanwhile, is unity. As they titled last week's post: “The grid needs a symphony, not a shouting match.”
See the comments posted with the original article:
It’s Been So Windy in Europe (June 2017) That (Wholesale) Electricity Prices Have Turned Negative
But we can't always rely on bad weather.
Editor's Note by the Arizona Solar Center:
This is one of the technical problems with renewable energy, sometimes the local utility (or even regional inter-tie area) will end up with more renewable energy than anticipated or useful. For many reasons local utilities do not generate all the energy their customers need. In the USA and Europe there are wholesale energy markets in which utilities and independent power producers buy and sell energy under contracts. There can be minimum and maximum power levels for specific time periods. System operators need to maintain a balance of generation vs. customer loads (not a simple task), and must consider the varying load characteristics of the various generation sources. As a result some suppliers may be told not to supply contracted power (and may receive compensation as a result), and adjoining utilities may be paid to accept some extra power.
In fact, with offshore wind supplying 10 percent of the total demand, energy prices wereknocked into the negativefor the longest period on record. The UK is home to the world's biggest wind farm, and thelargest wind turbines, so it's no surprise that this was an important factor in the country's energy mix.
"Negative prices aren't frequently observed," Joël Meggelaars, who works at renewable energy trade body WindEurope, told Motherboard over the phone. "It means a high supply and low demand."
Indeed, there were a few periods in recent days during which Denmark's supply of wind energy alone exceeded local demand—as much as 137 percent overnight when demand was lower.
In total, around two percent of Europe's total energy supply was being provided by offshore wind on Tuesday.
"That's a very high level," said Meggelaars.
Producing more energy than your country can use isn't always a bad thing. It often simply means that energy can be sold on to neighbors, as is frequently the case with Danish supplies to The Netherlands, Germany and Norway.
The news comes not long after it was revealed that, worldwide, renewables supplied a record 161 gigawatts of electricity in 2016—and ata price that was 23 percent cheaperthan it would have been in 2015.
Of course, one of the main features of energy sources such as wind that is made clear by this recent news is just how variable, or perhaps unreliable, it is. As a result, most countries still rely on more predictable sources of energy such as gas, nuclear, or biomass to provide their "base load"—the minimum demand on the electricity grid over time.
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About The Arizona Solar Center
Arizona Solar Center Mission- The mission of the Arizona Solar Center is to enhance the utilization of renewable energy, educate Arizona's residents on solar technology developments, support commerce and industry in the development of solar and other sustainable technologies and coordinate these efforts throughout the state of Arizona. About the Arizona Solar Center- The Arizona Solar Center (AzSC) provides a broad-based understanding of solar energy, especially as it pertains to Arizona. Registered…Read More