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Capitol Letters: The Sea-Change in Renewable Energy

By Marcia Martin Last week, the Longmont City Council approved a list of staff-recommended bills in the State Legislature which are of special interest to the city.
Capitol with Scaffolding
Colorado Capitol (Photo courtesy of Marcia Martin)

This content was originally published by the Longmont Observer and is licensed under a Creative Commons license.

By Marcia Martin

Last week, the Longmont City Council approved a list of staff-recommended
bills in the State Legislature which are of special interest to the city.

One of them, HB19-1003, Community Solar Gardens Modernization Act, amends the current statute which establishes local solar gardens. It increases the maximum allowed size of a community solar garden from 2 megawatts to 10 megawatts. The Longmont City
Council has voted to explicitly support this bill, a recommendation that traditionally carries weight with the members of the State Legislature. It’s already passed its first committee hearing and been referred to Appropriations, so there won’t be an urgent call to testify on behalf of this bill until it reaches the Senate. The bill’s sponsor is Representative
Chris Hansen of District 6, Denver.

A community solar garden is a smallish array of solar panels, which is situated local to the community that uses the power it generates, and which has at least ten community “subscribers” who pay for the power. They are efficient because they don’t use long, expensive transmission lines. State law exempts them from much regulation and requires that generation utilities such as XCEL and Black Hills permit them to be built in their
service area.

It’s worth looking deeper into why this bill is important to Longmont, especially since Longmont Power and Communication (LPC) has not put forward strong incentives for adopting local solar generation. The reason this may be about to change has some of its origins in a bill introduced by Boulder Senator Stephen Fenberg last year. SB 18-009
established the right of energy consumers in Colorado to install storage batteries, either with or without distributed generation capabilities such as rooftop solar panels or a
community solar garden. The batteries are what will be critical for Longmont.

Early last year, the Longmont City Council passed a Resolution to drive toward consuming only electricity produced by 100% renewable means by the year 2030. Even though Longmont doesn’t generate its own electricity, except for a few homes with rooftop solar panels, it’s the second biggest consumer in the Platte River Power Authority (PRPA). PRPA provides essentially all the power for the four owner cities of Fort Collins, Longmont, Loveland, and Estes Park. One by one, the other three cities followed Longmont’s lead, and on December 6, 2018, PRPA itself resolved to produce 100% non-carbon energy by 2030. This is, as Joe Biden would say, a big deal.

Today, PRPA generates less than 1/3 of its electricity from renewable (non-carbon) sources. But it’s now saying that by 2025, that number will approach 80%. And sometime between now and 2025, what it means to be a conscientious “green” consumer will change dramatically, for Longmont and for its residents.

Getting to 100% non-carbon generation, 100% renewable energy sources, is only one “pillar” of PRPA’s mission. Keeping rates low and equitable for consumers is another one. Renewable energy doesn’t pose too much of a problem there: after all, the fuel is free and comes out of the sky. But the pillar that means the most to a generation authority like PRPA, and to most consumers as well, is *Reliability*. And this one gets tougher as the
proportion of renewable energy resources increases. Generating electricity by burning coal gives a constant supply of power. If it’s not enough, you can fire up a gas turbine generator (a “peaker” plant) to give the supply a boost. High demand generally comes at predictable times, like on summer afternoons when people run their air conditioners.

Matching the supply to demand for electricity is a difficult problem, but it’s well understood. PRPA is good at it. But when the proportion of renewable generation exceeds 50%, things change. Renewable energy is intermittent. Sometimes it’s cloudy. Sometimes it’s calm. And these conditions of higher and lower renewable energy supply don’t always correspond nicely. Peaks in demand can occur during low points in supply. That’s something that PRPA
and LPC just can’t tolerate. We have to manage it. In the new world of renewable energy, matching *demand* to *supply* will be easier (and greener and cleaner) than matching *supply* to *demand*.

That brings us back to community solar gardens *and batteries*. This will be hard to hear, for responsible environmentalists who are conscientiously investing in rooftop or other local forms of solar generation. You did the right thing, being early adopters and creating the market that drove low-cost solar technology. But in the renewable grid of the very near
future, those solar panels don’t help much. They even become part of the problem: their production is highest just when PRPA’s solar farms will be at peak production, too. They’ll add to the energy glut that will now form on summer afternoons. That’s when energy will be nearly free. Extra energy will be needed when the sun sets, when we plug in our cars, and in the wee, dark, quiet hours of the early morning, when the world is waking up.

Here’s where a community solar garden *plus battery* can be so useful. The garden can use some of its solar power to charge its battery. It won’t matter that the extra energy the garden generates when the sun is shining is worth almost nothing (or less than nothing) to LPC. Because the garden subscribers win big by selling battery power to the grid when the energy supply is lowest. Give LPC a “remote control” for that battery, and it’s the best of all possible worlds because then it helps LPC and PRPA ensure that there’s a reliable supply of energy even when renewable output is at its lowest. Everybody wins. PRPA’s reliability concerns are addressed, the Solar Garden’s subscribers lower their energy costs, and we are not putting greenhouse gasses into the air to get it done.

Kudos to our state legislators, such as Senator Fenberg and Representative Hansen, for being forward-looking and laying the statutory groundwork we will need for managing the renewable grid of the future. I dearly hope to see Longmont follow suit with strong incentives for other types of battery+solar installations in homes and businesses.

Longmont residents are going to need to get smart about how they participate in attaining our citywide goal of 100% renewable energy by 2030. Adding solar panels was a
good first step, but by itself, it won’t solve the problems of tomorrow. The change is coming. Fast. Longmont will be leading the way. Isn’t it exciting?