This commentary is by Daniel Costin of Montpelier, who has been working in renewable energy since 2001, including many years at Northern Power Systems, a wind turbine manufacturer based in Vermont. For the past five years, he has been teaching mechanical engineering and renewable energy classes at Vermont Technical College.
Vermont’s electrical energy system is undergoing a dramatic transition due to the electrification of everything.
In the coming decades, we will be driving electric cars and heating our homes with electricity. At the same time, our electrical grid will be powered by more renewables, such as wind and solar. Electrification is the quickest way to reduce greenhouse gas emissions that are causing climate change.
I am fully in support of electrification, but doing it the wrong way will cost a lot more.
Expanding renewable energy generation is difficult and expensive. Policies have discouraged wind development. Even if we can change our policies to support the development of wind power in Vermont, we still have to pay for it.
A major cost of renewable development will be the loss of open land. Each wind turbine or solar panel has an impact. We are obligated to keep the impact to a minimum.
This brings us back to the question of how we electrify everything with the least impact. Electric heating using heat pumps is already making a difference in carbon emissions. Air-source heat pumps will heat your house for about half the cost of oil heat this winter. Ground-source heat pumps are even less expensive than air-source heat pumps, but the cost is mainly paid upfront in the form of construction costs. This upfront cost is a barrier, and as of 2020, there were only 690 installed in Vermont.
But the big benefit of ground-source heat pumps is that they are more efficient than air-source heat pumps, especially during the coldest days of winter. That means that fewer wind turbines and solar panels are needed to power the grid on the coldest days.
We don’t think much about electricity usage spiking in winter since we mainly heat with fossil fuels. As we electrify heating, the electricity that we use during the coldest days in winter will determine how much energy capacity we need. By 2030, the winter peak is predicted to be 10% higher than the summer peak.
So we should be using the cheapest and most efficient electric heating technology: ground-source heat pumps.
Efficiency Vermont has recognized the value of ground-source heat pumps and has provided incentives to help people get over the initial cost barrier. But more needs to be done. The reality is that the incentive system benefits the wealthy, who have the money to pay the upfront costs.
A more equitable solution is networked geothermal, where a utility owns the pipes in the ground and delivers water at about 50F. That is warm enough for a ground-source heat pump to work very efficiently. By paying the utility for the water by the month, the upfront cost is dramatically reduced, and more people can benefit from this technology.
Another benefit is that the utility can be the existing gas company, providing jobs for the declining fossil-gas workforce. In areas without a fossil-gas company, other entities may step in and form utilities to reduce the upfront cost of ground-source heating. In New York state, there are already seven electric and gas utilities that are setting up thermal utilities with pilot projects underway.
Another way of looking at this problem is to evaluate how much less renewable capacity would be needed if ground-source heat pumps, rather than air-source heat pumps, are implemented for a majority of buildings.
The increased efficiency of ground-source heat pumps during the coldest days, in 2050 when we plan to be net zero, will reduce the peak load by 21,000 megawatts, as compared to air-source heat pumps. That is not a typo. To put that in perspective, Vermont currently has 150 megawatts of wind turbines and 407 megawatts of solar panels installed.
We can invest in ground-source networks in our communities that are underground and out of sight, rather than paying for excess wind turbines and solar panels. To make this happen, we must pass a bill in the Vermont statehouse, the Ratepayer Protection and Thermal Energy Networks Act, which will allow the formation of regulated thermal utilities to equitably share this technology in cities, towns and neighborhoods around Vermont.
