Content provided courtesy of StraightUp Solar and ISEA Board President, Shannon Fulton

A common question in solar is “Why are you installing a 260 watt (W) solar module on a 215 W microinverter?” Or for central inverters, “Why is my system a 9,000 W system on a 8,000 W inverter?”

Solar modules don't produce their nameplate (DC) rating even with perfect sunlight that is perfectly oriented to the modules -- and even when this is approached, it's for very limited times in very specific, short-term situations.

When a solar module's nameplate says 300 watts, this means that in perfect conditions the module will produce 300 watts of power. In controlled conditions with a constant irradiance of 1,000 watts/sq. meter at 25 degrees Celsius or 77 degrees Fahrenheit, a manufacturer will measure how much power comes out of the module. This measurement is called Standard Test Conditions (STC for short), thus the nameplate rating is known as STC watts.

In the real world, the irradiance is usually lower and the temperature of the module is higher. The module production decreases with increase in temperature and decrease in irradiance. Dirt and soil covering the module will further reduce its production. The characteristics of each module in an array are never rigorously identical. Electrical losses occur due to slight differences caused by manufacturing imperfections, referred to as array mismatch loss.

The temperature loss, irradiance loss, dirt/soil loss and mismatch loss typically reduce an array's production by 20%. This is why the inverter is usually sized 80% of the array capacity.  There will be a few days in a year when the modules will receive bright sunlight on a cool day. On such days the array will exceed the maximum input power capacity of the inverter and the system will experience minimal power clipping on the inverter monitoring as shown below.

This only occurs a few times and over the short and long-term, driving the inverters to their maximum production maximizes financial return and keeps the customer's up-front costs down by not buying more inverter capacity than is actually needed.

Pop Quiz: What do You Get When You Install Solar on Schools?

By Amy Antoniolli, ISEA Board Member

If you answered smaller electricity bills, fewer greenhouse gases, and energy-savvy students, you are correct. On September 18, 2014, The Solar Foundation released the first of its kind review of solar in schools across the United States. The assessment, entitled Brighter Future: A Study on Solar in U.S. Schools, [1] shows that schools are installing solar, cutting utility bills, and using the savings to pay for teacher salaries and textbooks. 

Brighter Future identified 3,752 schools in the United States that have already installed solar energy systems, and according to the report, the potential for more is tremendous. The 3,752 schools with solar represent 3 percent of public and private K-12 schools and 5 percent of K-12 students in the U.S. [2]

The large, flat rooftops that typically characterize k-12 school buildings are excellent platforms for rooftop solar photovoltaic (PV) or solar thermal systems. The study estimates that more than 72,000 schools could potentially be candidates for cost-effective investment in solar. Solar installations on schools are a valuable opportunity for students to see science at work. They also provide hands-on tools for teachers to demonstrate scientific, technology, engineering, and math (STEM) concepts and inspire students to understand the value of renewable sources of energy.

Nationwide, the installed school PV systems have a combined capacity of 489,791 kW and are estimated at generating more than 642,000 MWh of electricity each year. To put this in context, the average American household uses 10.7 MWh of electricity each year. Generation from the PV systems currently in place on schools offsets the purchase of roughly $77.8 million worth of electricity per year. This combined energy value is roughly equivalent to 155,000 tablet computers or nearly 2,200 new teachers’ salaries per year. [3]

Illinois is listed as third in the number of photovoltaic installations on k-12 schools. However, Illinois ranks 22 in solar capacity. This seems to indicate that many of the installations on schools in Illinois are smaller and are likely used as demonstration and education systems.

The Solar Foundation performed an outstanding review of available information to produce this extensive and well-researched assessment. Note, however, there are some data errors.

Brighter Future listed my childrens’ elementary school as having a 10kW array installed in 2014, but the 10kW array was actually installed in 2002. The Solar Foundation recognizes that the information may not be complete and hopes to update it on a regular basis.

The cost of PV systems has dropped dramatically in recent years. Brighter Future shows that decreases in the average installed cost of solar have resulted in larger systems that not only provide educational value for students, but also significant cost savings for school districts. It is well-recognized that funding is the biggest obstacle for schools to go solar. The report shows, however, that schools are creative. The interviews of 15 representatives from solar schools showed that no school relied solely on direct cash payments for their systems. Any cash put into the project by the school – from bond measures, capital or operating budgets, or other means – were combined with other key forms of financial support, such as grants, loans, rebates, and SRECs. In Illinois, the Illinois Clean Energy Community Foundation and Climate Cycle are two Chicago-based organizations that offer funding opportunities for solar installations on schools in Illinois. These groups are led by engaging and knowledgeable individuals dedicated to advancing the use of solar in schools.

Overall, Brighter Future is a great first nationwide assessment and shows that the future for solar in U.S. schools is indeed bright.

[1] Brighter Future: A Study on Solar in U.S. Schools Report, Solar Energy Industries Association, Sept. 18, 2014 (“Brighter Future”).

[2] Of those, 3,727 were PV systems that turn sunlight into electricity. The remainder were solar heating and cooling systems that turn sunlight into heat which is typically used to heat water or air.

[3] Assuming an average tablet cost of $500 each and the 2011-2012 national average starting teacher salary of $35,672 (www.nea.org).    

About Amy Antoniolli

Amy Antoniolli is an attorney practicing environmental law at the national law firm Schiff Hardin LLP.  Amy routinely advises clients on compliance with environmental laws and regulations and represents clients before the Illinois Pollution Control Board.  Before coming to Schiff, Amy served as an attorney at the Illinois Pollution Control Board for five years where she advised board members on interpretations of Illinois environmental statutes and regulations, served as a hearing officer in regulatory matters, and wrote legal opinions in enforcement cases, permit appeals, and requests for relief from regulations.  Earlier in her career, she served as assistant counsel for the Speaker of the Illinois House of Representatives.  She volunteered with the k-12 education subcommittee in 2013 to help organize the first teacher’s workshop for fourth to sixth grade teachers and hopes to continue to expand ISEA’s educational resources in the future.

It Pays to Know Your Electric Supplier

by Michelle Knox, ISEA Board Member and daughter, Mikella Marley

Henry Wallace said, “In an effort to eliminate the possibility of any rival growing up, some monopolists would sacrifice democracy itself.” Fortunately, one of government’s roles is to preserve democratic rights, and Illinois took strides to dissolve a perceived monopoly by deregulating the electricity market. 

Illinois’ journey to electricity deregulation began before many citizens may realize. Over a decade ago, in 1997, state legislators passed the Illinois Electric Service Customer Choice and Rate Relief Law. These measures deregulated Illinois’ public utility providers (Ameren Illinois Utilities and Commonwealth Edison Co.), and presented customers with the option to procure electricity from approved Alternative Retail Energy Suppliers (ARES). 

Residential customers remained unaffected by these actions until 2006, when the General Assembly passed the Retail Electric Competition Act. This act promoted temporary, fixed-discount programs. It took several years for ARES to gain popularity with residential customers, lured by substantially lower rates than those offered by Ameren and ComEd since their rate caps had expired.

What many customers failed to realize was the transient nature of these enticing rates; as the temporary incentives expire, residential consumers have found themselves saddled with bills heftier than those they were attempting to escape by resorting to ARES in the first place. 

As a personal example, I converted from a public utility to an ARES in July of 2010 at a substantially lower rate. In 2012, the fleeting period during which I paid this reduced rate expired, and I began noticing gradual increases in my electric bill. Upon further investigation, it became apparent that reinstating my business with my public utility provider would actually save me a considerable amount of money (a reduction from $.1199/kWh to $.04657/kWh).

It’s worth noting the glaring irony of this deregulated marketundefinedpatrons resorted to ARES in an attempt to abscond from the financial confines of Illinois’ high public utility rates, only to ultimately find those very companies may now be offering the most competitive rates due to new procurement contracts they have entered into that allow them to purchase wholesale electricity at a less expensive rate and pass that savings on to consumers.

Before being blinded by sequins in your eyes skillfully placed in your field of vision by electricity providers in the form of dazzlingly low rates, take care to not only research that provider, but also gain a thorough understanding of your contract terms before you are locked into an agreement that will do anything but financially behoove you. 

Of course, there’s always the renewable energy option! Despite an obligatory flat rate “supply” fee applied to each month’s electric bill for all grid-tied customers, regardless of supplier and proportionate to usage (typically ranging from $30-70), renewable energy can help to offset this fluctuating market by allowing the system owner to supply all or a portion of their own power at a fixed cost over the lifetime of their system.

About Michelle Knox

Michelle is the founder and owner of WindSolarUSA, Inc., a turn-key renewable energy company located in Central Illinois, and a founding partner of American Solar Designs based out of Memphis, TN. She began research and development of WSU in September of 2008 with a goal of helping the residential, commercial, and agricultural markets to invest in their own clean energy future while attaining a desired level of self-sufficiency. Michelle received her training through the Midwest Renewable Energy Association in Custer, WI and is a Certified Site Assessor for both solar photovoltaics and solar thermal and has completed all phases of wind training. Prior to pursuing her renewable energy career, she was the Development Director (fundraiser/grant writer) for a private, east-side elementary school in Springfield and a Montessori teacher of 6-9-year-olds. Michelle is an advocate and promoter of renewable education and hopes to use her teaching and fundraising skills to further the advancement of the solar market statewide through her role on the board of the ISEA.

Moving Towards a Flexible Grid

By David Brochu, ISEA Board Member and Secretary

 

The electric power grid is an incredible feat of engineering. It connects thousands of generators to millions of customers, reliably delivering electricity to our homes, businesses, and critical infrastructure – flowing energy, from centralized generating resources such as coal plants, wind farms, nuclear and solar power plants. We take this nearly century-old system for granted and it rarely factors into conversations about how best to build a clean energy future. But this is a mistake.

 

A Gallup poll from April 2013 found that three-in-four Americans want the United States to pursue more solar energy and another 71 percent favor further development of wind power. Achieving a clean energy future will require modifying the current grid to be “flexible” so that it can accommodate more solar, wind, storage, and demand-side resources. Moving to a “flexible” grid means moving our existing grid infrastructure from the centralized generating resource model to a decentralized model – meaning a grid that optimally aligns energy consumers and generators, utilizing variable clean resources like solar and wind. Americans are already moving forward by installing solar on their homes and calling for further development of wind power. We’ve been moving forward towards our clean energy future, while the grid is not set up to utilize the power being generated most efficiently.

 

Historically, the reasons given for not pursuing higher levels of renewables are two-fold: cost and reliability. With regards to cost, renewables have made significant progress such that solar is now able to compete in Texas’ deregulated ERCOT market. In fact, across the country there are numerous examples of utilities requesting approval from their regulators to purchase wind and solar on the basis of economics rather than policy. More so, renewable energy isn’t subject to the volatile pricing that fuel based energy sources are, such as coal and natural gas, making more attractive to utilities and offtakers across the country.

 

On the reliability front, we have seen in practice that markets with a higher percent of renewable generation like CAISO are indeed able to ensure reliability and balance variability from renewables while preventing overgeneration, even with one fifth of the system’s power currently coming from renewables. While variable renewable resources of around 20% are shown to operate successfully, in order to move forward the grid will need to be more flexible to accommodate energy flowing two ways, from more sources, and with a higher percentage of variable resources. We are also now seeing IOUs stepping forward, after a 30 year hiatus, to invest in new infrastructure to address the coming waves of renewable generation and to address aging resources and the ability to remain resilient during natural disasters. As we reinvest in the old infrastructure, doesn’t it make sense to further strengthen our grid and ensure accommodation of more variable resources?

 

Investing in a “flexible grid” – one that can enable dynamic, two-way variable power flow and connect devices for dispatch and performance measurement - is critical for affordably and reliably integrating high levels of clean energy resources. Some examples of infrastructure that enables grid flexibility include technologies like energy storage and smart inverters; demand-side tools to help system operators to better reduce, forecast and control overall load; markets that value flexible generation capable of ramping up and down quickly; and more efficient regional integration. These flexibility resources will allow us to affordably and reliably deploy more renewable generation. 

 

Building a flexible grid won’t happen overnight. These updates to our grid system will be incremental and will involve technical, market, and regulatory complexities. But there’s no time like the present. The majority of Americans want a clean energy future, and a flexible grid is key to achieving it. 

About David Brochu

David Brochu is the Chief Operating Officer of Recurrent Energy, leading all project development, engineering, procurement, construction, operations and origination activities. Before assuming the role of Chief Operating Officer in June 2014, he served as Recurrent Energy’s Senior Vice President of Development for four years, where he oversaw all development activities. Prior to Recurrent Energy, David was President and CEO of UPC Solar, a Chicago-based solar PV developer with a pipeline of projects in Ontario, Canada and the United States.

His past experience includes Vice President of Sales and Marketing at SmartSignal Corporation (now a GE Company), where he negotiated turbine and power plant monitoring agreements with major US utilities; Executive Vice President at Acumence, a business intelligence software company; and Director of Sales at Wonderware Corporation, a leader in industrial automation software.

He graduated with a Bachelor of Science degree in Mechanical Engineering from Texas A&M University in 1985, and earned a Masters of Science in Mechanical Engineering from Stanford University in 1986.

What the PV Value® Assessment Tool Doesn’t Assess

By Peter Gorr, ISEA Board of Directors Member       

  

The added value to a home that a Solar PV system contributes is a very important component that can help offset the concern regarding the initial capital outlay required to purchase a solar system. I have always been a critic of anyone who presented a financial case for purchasing solar equipment that consisted of illustrating a payback period determined by dividing the cash outlay by the annual energy savings and nothing else. 

While the energy savings is important and perhaps the most obvious component to offset the cost of the system, real tangible value has been added to the home that will be recovered to some degree when the home is sold. These 2 items are a certainty so it is important to calculate them accurately. Additional items that can generate value but with less certainty and accuracy are the sRECs that the system will generate and potentially be sold and, perhaps the hardest to quantify, the importance (or premium) a potential owner places on using clean energy. For me and many people I meet, this last point is a significant driving force that led us to consider and eventually purchase a Solar PV system.    

Determining a home’s added value has been a challenge so I was happy to see an assessment tool developed, PV Value® (http://energy.sandia.gov/?page_id=8047). Unfortunately I was extremely disappointed to see how this model assessed the value of my system. Valuing a PV system with this tool is done using a discounted cash flow approach, which primarily considers the present value of projected future energy production. While I have no argument with this approach, to peg the total added value to the home using just this computation is incomplete. What is missing is indeed difficult if not impossible to model but should not be ignored.

As someone with a math degree and a MBA with a concentration in statistics, I certainly understand and respect the power of number crunching.  But my MBA also came with a concentration in Marketing and with over 30 years of sales and marketing experience I also understand and respect that there are some things you can’t input into a pricing model but if you ignore them you will leave serious money on the table if not lose the sale completely.  This something is called “perceived value”. Real or perceived, value is what people seek and determines what they are willing to pay. A skilled salesperson knows how to identify any and all value a system offers a prospective customer. And that’s my issue with PV Value®. It misses some real value and all of the perceived value that the system offers.

First let’s start with the missed real value namely potential SREC sales. While selling sRECs are far from certain as well as the price one might receive, sRECs do provide a potential source of income. Since my system was installed over 3 years ago, I have average $70/month in SREC sales income. PV Value® offers no way to account for this which undervalues my system in my opinion. With my energy savings almost the same ($68/mo),  PV Value® is undervaluing my system by more than one half. A way to add some value to the system for the income potential it offers the owner should be included. Certainly this should be the case in a state where there is a SREC market or potential to have one. I hate to state a problem and no solution, but I don’t know how to account for this value yet it has been real and I expect it to continue to generate some income.

Second is the perceived value of the system. Most people interested in Solar PV systems are motivated by a concern over climate change and want to lower their carbon emissions. This motivation is so great with some people, like me, that there is a willingness to pay a premium. How much of a premium is certainly subjective and again impossible to input into a model. But it is real enough to add value to the home. Studies indicating homes with solar systems sell faster suggest these homes offer something of higher value to set them apart and this desirable point of differentiation should command a premium.

In conclusion, PV Value® has a place in helping to determine the added value to a home of a Solar PV system but it offers only a part of the total assessment. It basically sets the minimum added value. The current and projected SREC income potential in a given state needs to be added in some fashion as well as the premium justified with a home that has significantly lower carbon and pollution emissions. These additional two other value generators push that assessment up, how high is primarily dependent on the potential buyer. When I add up all the real and perceived value I have received from installing a Solar PV system and compare it to the investment I made, I have always stated and will continue to state “It made me wealthier the day I flipped the switch”. This assessment is accurate, at least to me, and that’s what counts.

About Peter Gorr

 

Peter Gorr is a retired Director of Marketing, Product Management, and Business Development. He holds aMBA in Marketing and Statistics from the U of Chicago. He is currently the Chair for the NW Cook County Group of the Sierra Club and was recently elected to the state chapter Executive Committee.  He is active in local habitat restoration and is on the Board of Directors for Friends of Busse Woods and a founding member of Friends of Deer Grove East. He has been an active member of ISEA assisting the organization with promoting and hosting the Solar Tour, hosting 2012 Summer Social, as well as assisting at several events. His home features a 6.72kw Solar PV system which he has used as a platform to promote the benefits of clean renewable energy throughout the area with speaking engagements and advocating for pro-solar legislation with state representatives

Solar Energy in Illinois – Where Do We Stand?

 

By Glenn Reed, CPA

 ISEA Treasurer and Board Member

Where does Illinois stand compared to other states in terms of energy production-- especially solar? With 13 million people, Illinois ranks 5^th in population¹, but only 11^th in total energy production².

Where does Illinois’ energy come from? Mostly fossil fuels. We’re number one in the US for electricity produced from nuclear energy, and number three for coal². Not such a good thing when you consider that 90% of the uranium purchased for US commercial reactors comes from outside the US². Plus, Illinois is a net importer of coal, despite the fact that a huge amount of it is mined right here in our state³.

Another concern with coal is air pollution. Largely due to burning coal, Illinois is ranked 6^th in the nation for sulfur emissions² and 5^th for CO₂ emissions⁴. More than 38% of Illinois CO₂ emissions come directly from electric power generation⁴.

What about renewable energy? Illinois ranks 34^th in percentage of power generated by renewables⁵. Folks, we can do better!

That said, there is some good news on the renewables front. Illinois ranks 15^th in the nation in wind energy potential. We are in the top four states in terms of installed wind power, with more than 3,500 MW of installed capacity⁶. Way to go!

What about solar? The US has incredibly abundant solar energy at our fingertips-- nearly 400,000 TWh/year, or 100 times our total energy consumption in 2011⁷! Why not use it?

Is it sunny enough for solar to work here in Illiois? Absolutely. Mt. Prospect, Illinois has more solar irradiance than Miami, Florida during June, July, and August, measured in kWh/m²/day of sunlight falling onto a horizontal surface⁸. And we’re putting it to work. Illinois ranks 22^nd in installed solar capacity, with over 52MW. In 2013 alone, 2 MW of solar was installed here. Currently, there are over 184 solar installation and related companies in our state, employing over 2,100 people⁹.

Is solar growing? Absolutely. Over 4,750 MW of photovoltaic capacity was installed in the US in 2013-- a 41% increase over 2012. We just need to have more of that growth here in Illinois. In 2012, solar contributed to 10% of all new electricity generation capacity. In 2013, it jumped to 29%, making solar the second largest source of new electricity generating capacity, behind natural gas⁵.

Illinois can be a leader in renewables, as it has been in other forms of energy. Doing so will mean cleaner air, lower energy prices, and more jobs here in Illinois.

Sources

1. U.S. Census (2010 Actual, 2013 Estimate)
2. U.S. Energy Information Administration (eia.gov)
3. David Kashi, International Business Times, January 15, 2014
4. U.S. Environmental Protection Agency (epa.gov)
5. U.S Department of Energy (energy.gov)
6. American Wind Energy Association (awea.org)
7. Anthony Lopez, Billy Roberts, Donna Heimiller, Nate Blair, and Gian Porro, U.S. Renewable Energy Technical Potentials: A GIS-Based Analysis, National Renewable Energy Laboratory, Technical Report NREL/TP-6A20-51946, July 2012
8. Michael Boxwell, The Solar Electricity Handbook, 2014 Edition,Greenstream Publishing
9. Solar Energy Industry Association (seia.org)

Solar Brings Freedom from Traditional Technology

by Taylor Gendel, ISEA Intern

Independence Day is upon us and I couldn’t help but notice several new innovations in solar. Solar energy is everywhere and its presence gives us the possibility to become increasingly independent from other, less clean sources of energy. As technology expands, so do the opportunities to put panels in places that were never before possible.  Here are some recent ways to capture and use solar energy.

1. Cars: No, not electric cars that you can charge with a solar station. Actual cars that have solar panels on them! Here is a list complete with pictures. It includes a solar paneled golf cart, and a solar camper van! Imagine a camping trip where you could be completely isolated from humanity yet still have a power source.

2. Benches: In Boston, park benches will now charge your cell phone! The new solar benches, called Soofa, are a new project from Changing Environments, a group of 3 women from the MIT media lab. The solar seats have USB ports to charge electronics and send location-based data like air quality and noise level to their website.

3. Roads: By now you’ve probably seen one of your friends post this on Facebook, but a couple in Idaho is working on a way to cover roadways with solar panels! Solar Roadways have many innovative elements including heating abilities to melt snow and ice, five-color LED lighting to create road lines, and corridors for moving and storing storm water. The surface of the panels is made out of textured glass that can withstand 250,000 pounds. Solar Roadways has already received two phases of funding from the U.S. Federal Highway Administration for research and development. The roads are still in production but this is definitely a project to look out for!

AND NOW:

4. Pop-up Solar Stations: The Ecos Powercube is a fully functioning solar-powered energy station. It is transportable and can be used for disaster relief, in refugee situations, and all around the world. It has wifi capability for up to 30 miles, a small wind turbine which adds to the energy stored in onboard batteries for later use, and it can draw moisture from the air to make clean drinking water. If that’s not enough it also opens up to a space inside that can function as a temporary shelter, school, or medical center AND it can act as a generator to power other buildings. Sounds like a win win win win win win win….you get it.

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Taylor Gendel is ISEA's Program Development Intern. She graduated from the University of Wisconsin-Madison in 2013 with a degree in Community and Environmental Sociology and an Environmental Studies certificate. She is originally from Evanston, IL.