Keeping It Local: "Behind the Meter" Alternatives for Growing Low-Carbon Electricity
Working on your side of the meter allows creative solutions
We have access to much more solar energy than we need to meet global or U.S. demand for low-carbon or renewable electricity. That sounds like an exorbitant claim, so exorbitant that I have repeated the calculation several times, just to be sure. The results were presented in a previous essay. Elon Musk, among others, has said the same thing. The bottom line is that a total solar panel area equivalent to about 1% of the land area of the U.S. could produce enough electricity to meet all the country's energy needs.
Not all of those panels need to be on new sites or cover areas not already used for other purposes. All rooftops in the U.S. alone could generate 19% of total national energy demand and parking lots could add another 18%. Or how about converting all the farmland now used to grow corn that is converted to ethanol for use as a gasoline additive? Just over 50% of that land converted to solar collectors would be enough. And as the national vehicle fleet is converted to all-electric over the next couple of decades, the demand for ethanol should decline precipitously.
So when Bill Gates tells us (in How to Avoid a Climate Disaster) that electrifying the economy and developing low-carbon sources of electricity is the solution, the potential seems to be there to realize that vision. However, the reality to date reflects Vaclav Smil's view (in How the World Really Works) that changes in the global energy system happen very slowly.
If low-carbon electricity is our goal, there are two very different economic and technological pathways toward that goal, and the utility company's meter that measures your use of electricity is the very visible dividing line between them.
On the utility's side of your meter, most electrical energy is produced at large, centralized power plants and is delivered through the complex, continental-scale “grid” managed by large corporations and government agencies. "Gridlock" in this system is currently restricting the rate of addition of new renewable sources. Solar, wind, and hydro now make up only about 19% of total electricity production in the U.S. and these low-carbon sources are growing slowly at this centralized, industrial scale.
But then there is "Behind the Meter" energy - any generation or storage of electric energy that happens on your (the consumer's) side of the meter. These are mostly small-scale systems at the home, building, community, or company/institutional level that are planned and built by individuals, neighborhoods, and local enterprises.
Much of the energy produced at this scale is used on site, reducing the customer's energy bill as well as reducing the demand on the grid and the fossil fuel combustion that drives the grid. Most systems, but not all, also maintain a connection through the meter to a local utility such that energy can move either from or to the customer. "Net Metering" is the term used to describe this net flow of energy.
Most Behind the Meter systems are relatively small scale, but an earlier essay here described how one of the world's largest iron mining concerns plans to use both wind and solar directly in their operations, and also to create green hydrogen for use and export, so small-scale is not a requirement! Those smaller systems are mostly solar, as wind or hydro projects are difficult to down-scale, but there are a variety of creative ways to generate, use, and store low-carbon energy. One described here uses methane derived from a major landfill.
Despite the abundance of available solar energy, only about 4% of electricity in the U.S. is produced from this source. About 36% of that is at the residential, commercial or community scale, and most of that is "Behind the Meter." This would include almost all the rooftop systems you see, as well as some of the smaller stand-alone systems.
The scope of existing energy systems out there Behind the Meter defies easy categorization, demonstrating the possibilities for creative solutions. All I can do in this essay format is sketch six examples, all from snowy, cloudy, and cold New England, not all of them solar, that capture some of the range of possibilities. Similar approaches should be even easier in warmer and sunnier places!
The examples captured in the images in the Behind the Meter figure above and discussed here include:
- A standard residential rooftop installation.
- A resort complex using all locally produced electricity to reduce draw from the grid.
- A community-level installation supported by several households
- A new middle school that is generating more energy than it uses
- One university capturing solar energy with parking lot canopies
- And another using alternate fuel sources and advanced technologies
This short list only hints at the creativity allowed by working Behind the Meter!
A problem frequently cited for wind and solar energy is that, on either side of the meter, interactions with the grid can become complicated. Grid operators no longer have a direct connection to the source of energy they need to distribute, and the production of energy from this distributed system can be highly variable over time.
The most straightforward solution to this limitation is installing systems for storing solar and wind energy for later use. Large, community-level battery systems are beginning to appear, and residence-scale solar systems are now generally offered with battery-included options. An earlier essay highlighted some of the more creative approaches that have been taken to storing energy from intermittent sources.
One of the most intriguing storage options is building electric vehicles (EVs) capable of moving electricity both to and from a building's system. Imagine a home where solar panels feed electrical storage in the batteries of a car, that can then be tapped for use as a source of electricity to the home in dark periods (or during power outages). The total storage capacity of the millions of EVs likely to be built over the next couple of decades is immense. A recent professional assessment (see Sources below) suggests that grid stability could be achieved if less than half of EVs include this kind of two-way connection.
Given the two-sided nature of renewable electricity production (both in front of and behind the meter) it appears we have more than enough ways to produce, store and distribute all the low-carbon electricity we need.
Sources
The first figure on potential solar energy yield is from a previous essay entitled "We Are Flooded with Renewable Energy Every Day." //lessheatmorelight.substack.com/p/we-are-flooded-with-renewable-energy
In this promotional article, Elon Musk says the amount of land area needed to meet total U.S. energy demand through solar capture is equivalent to the size of Lake Erie.
https://elements.visualcapitalist.com/how-much-land-power-us-solar/
The images in the second and third figures are from:
https://www.iea.org/reports/coal-fired-electricity
https://commons.wikimedia.org/wiki/File:Wind_turbines_in_southern_California_2016.jpg
https://www.nrel.gov/news/program/2022/increased-spacing-of-solar-panels-comes-with-benefits.html
https://www.energy.gov/energysaver/grid-connected-renewable-energy-systems
https://commons.wikimedia.org/wiki/File:Westmill_Solar_Cooperative_1.jpg
https://www.epa.gov/chp/what-chp
https://www.businessnhmagazine.com/article/oyster-river-school-boasts-sustainable-design
https://www.eia.gov/energyexplained/electricity/delivery-to-consumers.php
https://www.umass.edu/sustainability/robsham-visitor-center-solar-canopies
https://www.unh.edu/sustainability/campus-initiatives/energy
Here is a good article on Behind the Meter energy:
https://www.nrel.gov/docs/fy21osti/79393.pdf
Bill Gates proposes the all-electric economy with low-carbon sources of electricity in:
Gates, B. 2021. How to Avoid a Climate Disaster. Alfred A. Knopf.
And Vaclav Smil describes the very slow changes that happen in energy systems in:
Smil, V. 2022. How the World Really Works. Viking
The figure on cumulative solar installations is from
https://www.seia.org/solar-industry-research-data
Sources for cost and payback period for rooftop systems in New Hampshire include:
https://www.energysage.com/local-data/solar-panel-cost/nh/
Data on the project at the New Hampshire resort are from a proposal by Revision Energy.
The Charlestown NH community solar installation is described here:
https://norwichsolar.com/community-solar-project-in-charlestown-nh-2/
One story about the Oyster River Middle School experience is:
https://www.orcsd.org/news/what_s_new/orms_leed_gold
The solar canopies at the University of Massachusetts in Amherst are described here:
https://www.umass.edu/sustainability/robsham-visitor-center-solar-canopies
The University of New Hampshire combined heat and power system and the connection to methane production at a regional landfill is described here:
https://www.unh.edu/sustainability/ecoline
An example of community-level battery storage is:
One clever presentation of the impact of increased solar energy production on management of the grid is termed "The Duck Curve":
https://www.energy.gov/eere/articles/confronting-duck-curve-how-address-over-generation-solar-energy
The recent professional analysis of the potential for grid stabilization through electricity storage in the batteries of electric vehicles (EVs) is here:
https://www.nature.com/articles/s41467-022-35393-0