When you charge your electric car matters. Charging when overall demand for electricity is low reduces costs and emissions for the electric grid as a whole. For years, we’ve advocated for better “smart charging” programs from our electric utilities to incentivize electric vehicle (EV) owners to charge their cars off-peak. In addition to utility programs, EV drivers in Massachusetts can participate in the Clean Peak Standard to earn rewards for charging off-peak.

Rhode Islanders, read on for interesting information, but the Clean Peak Standard program we explain here does not exist in Rhode Island. The only smart charging program available in the Ocean State is Rhode Island Energy’s EV Demand Response program.

First, Remind Me: What Utility Programs Exist?

When we talk about “smart charging”, we mean charging your EV at times that reduce emissions and costs for the electric grid. In our region, that mostly means overnight – and definitely not on the handful of summer afternoons where electricity use is so high that we reach peak energy use levels for the whole year. If you need a refresher on the concept, we recommend the first 15 minutes of this webinar we held a couple of years ago.

Right now, different utilities in Massachusetts offer different smart charging programs: 

• National Grid has an off-peak charging rebate program that offers $0.05/kWh of savings during off-peak times in summer months and $0.03/kWh in savings during off-peak times in winter months. (We’ve advocated for years that those incentives should be higher.) 
• Many, but not all, municipal light plants (MLPs) offer off-peak charging rebates or time-of-use rates for EVs. Check your MLP for more details! 
• Unitil offers time-of-use rates. 
• Eversource doesn’t currently offer any smart charging program, but recently proposed one to the Department of Public Utilities, which you can learn more about in this recent blog post. 

What’s The Clean Peak Standard? 

The Clean Peak Standard (CPS) is a Massachusetts policy that offers incentives to entities that can supply electricity or reduce demand when electricity demand is at a seasonal peak. The thinking is: why pay for an expensive and polluting oil or coal plant to turn on for just a couple of hours over the course of a year when we could pay less per unit of electricity to temporarily reduce demand or draw energy from, for example, stationary batteries? 

EVs are a great asset when it comes to reducing peak demand. It’s very easy to pause charging for a couple of hours during a peak event, and some EVs (mostly heavy-duty vehicles, like school buses) are already discharging electricity back onto the grid during peak moments. We look forward to the day when passenger vehicles can do the same.  

So that begs the question: If you have an EV, how do you participate in the CPS? 

How Can I Participate & Save On Charging? 

Individual consumers technically can sign up for the CPS one-by-one by applying on the Department of Energy Resources website. However, it’s much easier to go through one of the companies that is aggregating EV drivers to participate in the CPS. Here are two we found: ev.energy and Optiwatt.

Both apps control your charging during peak events and always give you the option of overriding. We compared some key stats for the two programs and did some math for what would happen with a vehicle that 

1. Charges off-peak 100% of the time, 
2. Has an efficiency of 33 kWh/100 miles, and 
3. Drives 10,000 miles/year.

Consumers are not able to sign up for a Clean Peak Standard and utility program at the same time. 

Image courtesy of ev.energy

Why We Need To Clean The Peak 

Peaker plants operate for less than 15 percent of the year and are called into action only when there is a particularly high demand on the electrical grid. Otherwise, peaker plants – which typically run on natural gas and use oil as a backup – remain idle. The plants’ rapid ramp-up and shutoffs can make them less efficient at controlling pollution output and make them “dirtier” than non-peaker plants, meaning they release more greenhouse gas emissions per unit of electricity and particularly burden surrounding communities with harmful air pollution. A new report pinpoints six peaker plants in Massachusetts that might be good candidates for conversion to clean energy resources. Many are located in environmental justice communities. 

Data Source: U.S. EIA. 2023. "Power Plants."

So, Let’s Charge Smart 

Managing EV charging through smart charging programs is cited as a key policy in every major climate planning document we have read over the past several years. By making sure EVs don’t charge on-peak, we can avoid costly infrastructure upgrades and turn off the spigot on  the notorious “peaker plants” dotted around the state.  

If you sign up for one of these services, let us know how it goes! We’d love to hear from you.