The Crestone Eagle • May, 2020

Community solar microgrids explained

by Paul Shippee

Going green with community solar microgrids is an increasingly popular strategy at the local level for solving, or at least mitigating, many of our electrical energy supply, consumption and safety problems. Resilience and sustainability become real benefits at the community level when we can enjoy locally produced and dependable renewable energy from natural sources like the sun and wind. Community solar microgrids that produce large quantities of renewable energy also offer non-local benefits to our planet by replacing dirty fossil fuel burning and by helping to modernize our national grid system. This is the wave of the future and the sooner we get on with it the easier and more successful will be our efforts to mitigate climate emergencies.

The grid

The national electric utility grid is in trouble. It has many growing problems that may not be visible to the casual observer. It is old, entrenched in its rigid economy, increasingly vulnerable, and unreliable. It is a top-down, monolithic monopoly cash cow in need of change to become modernized, ie, transparent, flexible, secure, truly community-oriented, resilient and graciously supportive of the new waves of renewable energy that are increasingly supported and demanded in the public interest world wide.

Little grids

Community Solar Microgrids, or “little grids,” can offer relief to all. They may be defined as a group of local consumers, served by the main grid, who build a local and large solar installation whose main purpose is to provide power to the community whenever the main grid goes down. Sounds great, doesn’t it? How it works is both simple and complex: main grid outages, blackouts or emergencies are events that automatically and immediately trigger sophisticated software and electronic switches that direct solar power from the large local array to serve the community. In this way, the Community Solar Microgrid can isolate or “island” from the main grid and maintain power to the community. And when the grid is up and running smoothly this local solar array then sells its power back into the main grid. In order to be fully functional, a Community Solar Microgrid must have battery storage standing by to supply energy to the community, or to the grid, as needed at night and on cloudy days. A “community,” in this case, may be defined as a neighborhood, small town, hospital, military base, ski resort, etc.

New designs

Specifically, a typical source of local solar electrical energy supporting a microgrid might, for example, be a large array (1-2 megawatts) of concentrating photovoltaic panels (CPV.) New designs presently deliver high efficiencies of over 30%, twice that of conventional rooftop solar panels.

Essential partnerships

Needless to say, a community solar microgrid of this large size will require public-private partnerships for funding, investments, construction management, and sophisticated electronics along with advanced software design to provide high quality, cost-effective energy systems integration. Beyond that, cooperation with electric distribution utilities (that may be investor-owned or co-ops) is required in this scheme in order to navigate some intricate and knotty hurdles. For example, adjustments to longstanding ways of doing business as usual may be in order, including revising existing contractual obligations as well as potential upgrading of grid physical infrastructure that increase the integration capacity of a substation to accept a daily supply of renewably sourced energy.

Grid impacts

Naturally intermittent and variable solar or wind energies present new and unfamiliar wiggles that the main grid is presently not equipped for. Grid impact studies are being done on large experimental solar arrays to assess grid integration capacity problems. These are sometimes highly secret reports owned by the large utilities. In any case, grid “system impact studies” are routinely part of the design process to assess in advance any upgrades, improvements and adjustments needed to prevent flooding the grid with more renewable energy surges than it was designed to handle.

In the public interest

It might be hard to understand why anyone would resist such promising introductions of safe, clean and earth-friendly, renewable energies into our society. At the same time, let us consider why so many utility companies are still resisting these inevitable innovations. From their point of view, receiving the rapidly sprouting, intermittent and variable renewable sources into their historically steady and reliable mix of fossil fuels is a huge change, including a loss of consumer revenue, and many, but not all, seem unwilling and unready to scramble to meet the new challenges. On the other hand, our culture is changing rapidly; meeting the public interest values of this sea change such as community choice, energy supply competition, fair rate design, clean energy and affordable prices is indeed a great challenge. The task ahead is to create a win-win outcome for both sides through dialogue, cooperation and partnership. After all, there is no time to lose!

Bringing it all back home

Bringing it all back home, a local group of five of us have formed a Microgrid Working Group (MWG) in order to explore the many aspects and potentials of our own Community Solar Microgrid. Interestingly, in addition to the solar aspect, the Crestone Baca Water and Sanitation District appears to have untapped potential for harvesting electrical power from its pumped storage of water in tanks installed up on the mountains for domestic use. We are looking into the technical and economic feasibility of such a water storage scheme that may also have potential for integration into a large solar array by increasing the flexibility of a Community Solar Microgrid. By the way, our water and sanitation utility is already a kind of microgrid as it has a large propane generator that can keep the pumps and data computers running during a grid outage! So there is your tangible local model of a microgrid. Seeking grant monies for funding such a mix of bold, local, alternative energy community initiatives is also underway within our MWG.

A Crestone microgrid

Crestone appears to be an ideal setup for our own Crestone Community Solar Microgrid. This is due to its rural location, mix of solar and hydro, plenty of sunshine, and ideal population size for a pioneering research and development solar microgrid model. All of this may appear to be attractive grounds for interested government advanced research funding. The cost of the large array of solar panels may also be attractive to private investors who seek to own solar panels for the benefit of the investment tax credit.

Other resources

In addition to these resources, we have reached out to Luis Reyes, CEO of the Kit Carson Rural Electric Cooperative (REC) located in Taos, New Mexico, for both in-person and telephone discussions. A few years ago Mr. Reyes led the first co-op utility to cancel their contract with Tri-State Generation and Transmission company, our regional co-op utility supplier of energy. Due to innovative arrangements with the Guzman solar investment company, Kit Carson has installed many solar arrays around Taos and appears to be successfully on track to supply all of Taos’ daytime electrical needs with solar energy. With his demonstrated commitment to deploying renewable energy from solar and wind power we wanted to make a relationship with our neighbor to the south for advice, assistance and mutual exchange of information. Mr. Reyes has expressed a warm willingness to assist Crestone aspirations in any way he can.

An electric society

We are increasingly a country that runs on electricity, an interesting addiction if you will, with ever-new applications coming along like electric vehicles (EVs) and all-electric, new building code standards. Hopefully, going forward we will have more to share and look forward to in this exciting time of earth-friendly initiatives.