“What is the Electric Grid?“
“Can the Electric Grid handle all these EVs and Heat Pumps?”
These questions come up frequently, and in this article, we’ll try to answer them!
Think of the electric grid as a puzzle with many interlocking pieces:
- Sources of electricity (generation)
- Systems that deliver that electricity to our homes and businesses (transmission and distribution)
- New technologies that allow our devices, appliances, energy storage, and vehicles to adapt their usage and share energy in response to current conditions on the grid (demand response).
- People! Power companies, state regulators, and regional grid operators
- All these things need to work seamlessly together for an efficient, reliable grid.
Generation - The Source of Our Electricity
Vermont leads the nation with its generation of electricity using carbon-free, renewable sources. In fact, almost 100% of the power produced in our state was from renewable sources in 2021. This doesn’t cover all of Vermont’s electric consumption needs as a large amount of electricity is imported from other New England states and Quebec. Even with this out-of-state generation, less than 10% of the electricity we consume comes from fossil-fuel sources. For comparison, the overall mix in the United States is about 20% coal, 40% natural gas, 20% nuclear, and 20% renewable.
Transmission and Distribution - Delivering the Power
In Vermont, responsibility for maintaining the electricity transmission infrastructure belongs to the Vermont Electric Power Company (VELCO). VELCO is responsible for over 700 miles of transmission lines, including those that are visible in several parts of Williston. VELCO’s most recent long-range (20-year) plan calls out the need for investment to handle increasing demand from home electrification and electric vehicles, among other things. Even with this expected demand growth, VELCO’s plan says the Vermont transmission system has sufficient capacity for the next 10 years. The investments we make now will be to support the needs of 2030 and beyond.
VELCO’s most recent long-range plan is available here:https://www.velco.com/assets/documents/2021%20VLRTP%20to%20PUC_FINAL.pdf
How We Pay For The Grid
The rates we all pay on our electric bill are approved each year by the Vermont Public Utility Commission (PUC). Power companies propose these rates based on a number of factors, including the cost of generating electricity and expected peak demands. Vermont is fortunate to rely primarily on renewable and carbon-free sources of electricity, as most of New England is currently experiencing large rate increases (many over 60%) due to the costs of Natural Gas. Meanwhile, customers of Green Mountain Power will only see a 2% increase.
The cost of electricity is not constant. Like many other goods and services we buy, electricity is sold on a market that responds to supplies and demands. It may appear as a fixed rate on our bills, but the cost of our electricity can vary significantly between a sunny day in the spring and a cold winter evening or a hot, muggy, summer afternoon. These high demand (and high cost!) times are called “peak events.” Power companies plan for these events when they submit their rates to the PUC. As a result, reducing these energy peaks can have an important impact on future rates.
You can learn more about what the Vermont PUC does and how you can participate on their website: https://puc.vermont.gov/electric.
A Smarter Grid
Beyond generating more electricity, how else can we handle our growing electric demand? Some big things to focus on are energy storage, energy efficiency, and demand response programs.
Energy storage (batteries) makes the grid more flexible, keeping the lights on during severe weather while reducing costs (and carbon emissions) for all customers during energy peaks. Last year alone, Green Mountain Power customers saved $3 million through GMPs network of stored energy.
Energy efficiency is key to making sure that even as we’re putting more loads on the grid we’re not doing so unnecessarily. Efficiency can take many forms, from replacing incandescent light bulbs with LEDs, turning lights and devices off when not in use, and weatherizing our homes.
Demand Response may not be familiar to most people, but it’s an important tool we can use to manage our grid. Demand Response programs make use of “smart” devices, including EV chargers, thermostats, home battery storage, etc., to automatically make these changes a few times a month during peak events, decreasing overall grid costs, delivering financial incentives to electric customers, and having little to no impact on our daily lives.
One example of Demand Response is in adjusting thermostats up or down a few degrees at peak times, or, better yet, pre-heating and pre-cooling our living and working spaces to take advantage of plentiful energy during off-peak hours of the day. This work is happening in Vermont now. The Flexible Load Management program launched by GMP and Efficiency Vermont does this by helping large businesses shift their facilities’ heating, cooling, and operations in ways to benefit the grid, and to save them money, maximize efficiency, and cut carbon emissions. Similarly, some local utilities offer special discount rates for EV drivers to encourage off-peak charging.
Beyond Vermont
Vermont is not an island when it comes to its electric systems. It is part of a larger, regional grid managed by Independent System Operator - New England (ISO-NE). ISO-NE is one of many Independent System Operators (ISOs) or Regional Transmission Operators (RTOs) in the United States. These groups are responsible for ensuring that the electric demand in their respective regions is matched by an appropriate level of electric supply.
You can view real-time conditions on the New England grid on ISO-NE’s website: https://www.iso-ne.com/isoexpress/web/charts.
You can also learn more about ISO-NE’s long range plans to support the New England grid in their 2022 Regional Electricity Outlook: https://www.iso-ne.com/static-assets/documents/2022/06/2022_reo.pdf.
The Future
As you can see, there are a lot of things to discuss when it comes to “the grid,” and there are also a lot of changes to be made. This grid transformation work is happening in Vermont now, and it is making a difference. More is needed however to provide the flexible and fully resilient grid Vermont needs.
If you’d like to learn more, this is a great article that goes more in-depth on all aspects of the national grid: https://justenergy.com/blog/power-grid-what-is-it-and-how-does-it-work/.
The Williston Energy Committee would like to thank Green Mountain Power for their contribution to this article.
To participate in Williston’s energy future, reach out to your Williston Energy Committee at Energy@WillistonVT.org or attend one of our public meetings, held on the second and fourth Wednesdays of each month. The agenda for upcoming meetings is posted on the Town of Williston website and on Front Porch Forum.