How home solar helps everyone

Solar power not only saves on current generation of high-cost power; it reduces the need for future generating capacity. My own home system shows that.

IPP parody — apologies to Peanuts and the late Charles Shultz

It was a hot and sunny month. … No, this isn’t the opening line of a bad novel; it’s a story about electricity and climate change, and our backyard solar array.

July was indeed hot, which means it was a costly month for electric generation. When the heat index pushes over 100 degrees, and homes and businesses run their air conditioning full tilt, utilities have to purchase more expensive power, from less efficient generating stations, to meet the higher demand. Their costs, and the costs for every consumer, go up.

But here’s the good news. It was a sunny month, which means all those solar arrays at farms and businesses and in people’s back yards were generating power at a great rate. The recently installed array at our home generated 1,749 kilowatt hours of electricity from late June through late July. That was 510 kWh more than we used, for which we received a $14 credit from the utility. (When I use more electricity than I generate, I pay over 12 cents per kWh for the extra; when I generate more than I use, the utility pays me 2.8 cents per kWh.)

But all of that electricity we generated meant that the utility needed to purchase 1,749 kWh less power from the grid, power that was more expensive than average. That savings equates to about the amount of electricity used by two average residential customers in a month.

In the last session of the Iowa Legislature, MidAmerican Energy pushed a bill that would allow them to charge an extra monthly fee to future solar generators, people pretty much like us. That fee would have been enough to make installation of solar unattractive to many, which in turn would have devastated the growing solar installation industry in the state. Their rationale: People like me aren’t paying their share of costs for using the utility’s transmission facilities to sell our home-generated power back to the utility.

Every month I pay a $13.50 “facility charge” regardless of our usage or solar generation. The Iowa Utilities Board, which has to approve all changes in rates proposed by Iowa regulated utilities, is scheduled to undertake a study to see if these kinds of facility charges appropriately reflect the utilities’ cost of accommodating solar generation. But MidAmerican’s proposed bill would have pre-empted the normal rate-setting process with the utilities board and imposed the new fee by legislative fiat before the study was even undertaken to see if any fee was justified.

In pushing their bill, the utility or some unidentified group, sponsored TV advertising to try to get the average Iowan riled up by convincing them that they are subsidizing solar users.

But here’s the thing: Iowa is a summer peaking state. Despite the longer winter heating season, the summer air conditioning season is when electricity usage hits its daily or hourly maximum. All utilities use their most efficient, lower cost generating facilities first, and bring the higher cost facilities on line only when needed. So those high-cost facilities are brought into use just when solar power is doing its thing, when the hours of sunshine are greatest. That reduces the need for that high-cost power, which helps all utility customers.

More importantly, those summer peaks are likely to get worse as climate change worsens. Solar power not only saves on current generation of high-cost power; it reduces the need for future generating capacity by helping to reverse the trend of global warming. That is good not just for electricity consumers, but for the planet and for our grandchildren.

Peter Fisher is research director of the nonpartisan Iowa Policy Project. pfisher@iowapolicyproject.org

Solar power shines when most needed

Distributed solar is good for the environment because the electricity produced is clean. It also is likely to come just when it is needed. Let’s make sure we have the policies in place to encourage more solar.

By David Osterberg and Nathaniel Baer

The hot sun we experienced this August not only caused the local electric grid to experience high use, but it also powered solar systems distributed around Eastern Iowa.

The middle of a hot summer day is a time when almost any U.S. electric utility expects to see highest demands during the year. Aug. 11 was going to be one of those days in Eastern Iowa. Peak demands of high electricity use translate to high costs.

So, a day in advance, MidAmerican Energy asked the University of Iowa’s Facilities Management team to cut back the university’s electric load from 12:30 p.m. to 5 p.m. on Aug. 11, 2016.

The university has an arrangement with the electric utility to decrease its electric load by cutting back on air conditioning and other usage, when called upon, in exchange for a reduced electric rate. The goal is to reduce costs for all utility customers by encouraging some customers to reduce their electricity use at the highest and most expensive times.

This type of arrangement is a win-win not only for UI and MidAmerican, but also other MidAmerican customers. Utilities often make these arrangements available to large customers as well as residential customers with air conditioning.

The university has two small solar energy systems that produce electricity. The data for one of them, a 38-kilowatt solar array, showed energy production varying during the morning of Aug. 11 (below). During the utility’s predicted peak period of energy use, the solar array’s production rose quickly and continued to be strong for the remaining period.

Basic RGB

Similarly, the solar arrays at Johnson County’s Secondary Roads and SEATS campus began producing much higher levels of solar energy shortly after the 12:30 p.m. high-use period started. These panels also continued with strong production through 5 p.m., when the period ended. (below)

160822-solar-timeofday

The hot sun caused the MidAmerican system to experience a peak day but also powered distributed solar systems in the area to help meet those higher energy needs.

Distributed solar is good for the environment because the electricity produced is clean. It also is likely to come just when it is needed. Let’s make sure we have the policies in place to encourage more solar.

2016-osterberg_5464David Osterberg is an energy and environment researcher at the Iowa Policy Project. dosterberg@iowapolicyproject.org

 

OLYMPUS DIGITAL CAMERANathaniel Baer is the energy program director at the Iowa Environmental Council. baer@iaenvironment.org.

 

A version of this column ran in the Sept. 6 Cedar Rapids Gazette.