Dartmouth professors seek to revolutionize the energy grid
Internet of Things could automatically run appliances during off-peak hours
Photograph by John Sherman
Dartmouth professors, Geoffrey Parker and Amro Farid, are exploring how to capture excess power and put it back into the energy grid, according to Dartmouth Engineer Magazine. They say the move would not only make the grid more efficient, but increase the ability to use renewable energy resources.
In 2015, the pair was approached by the New York State Energy Research and Development Authority, which asked them to propose a market to make the state’s energy system more efficient.
Over the next year, the two worked with colleagues from the energy and economics consulting group Tabors, Caramanis and Rudkevich to sketch out a white paper that focused not on the large power plants upstate, but on the thousands of smaller sources of energy scattered throughout the state, including photovoltaic solar cells, Tesla batteries and microgenerators. They found that these distributed energy resources could be key to revolutionizing the energy grid by constructing a network to allow them to coordinate with one another.
They argue the grid consists of three different types of power: real energy, reactive power (which helps balance fluctuations and helps keep alternating currents in phase) and reserve power, which kicks in when supply is low in order to prevent outages.
That reserve power is key to using renewable energy sources, such as solar and wind power, says Amro Farid, an associate professor of engineering who joined the Thayer faculty in 2015 and has similarly explored the creation of a smart-grid distributed energy network.
“With fossil-fuel generation, you can dispatch power at will and always keep the lights on, regardless of demand, and frankly at whatever price,” says Farid.
Renewables, however, depend on the weather.
As Parker explains, “If a cloud comes through or the wind dies, we saw in Texas a 3 gigawatt drop in generation over the course of an hour—that’s the equivalent of losing six natural gas combined cycle plants.”
Most power systems employ complex, expensive machinery, such as natural gas combustion turbines that are available 24 hours a day so that they can quickly respond to an emergency.
Farid recently worked to create a formula to determine that amount. The formula calculates the amount of reserve energy needed to keep the grid operating stably, based on a number of factors, including the percentage of renewables in the grid and the historical accuracy of predicting the energy load.
That’s where distributed energy resources come in. By creating a network that connects the need for reserve power with supply from thousands of distributed energy resources, theoretically the supply and demand could be matched the same way Uber matches drivers and passengers. That, in turn, would dramatically decrease the need for big machinery to respond to fluctuations in renewable energy generation.
“If you had the ability to coordinate a lot of little actors, you could avoid a lot of really big capital investments, and hopefully better accommodate some of the variability coming out of the system with renewables,” says Parker.
Those resources could also be anything that is currently storing power it is not using—including big buildings or even households running heating, air conditioning or other energy intensive appliances.
“If the wind dies off, you can tell them to back off a little bit. That 20 or 30 minutes might be all you need to get some larger equipment going or reduce demand in other parts of the system,” says Parker.
That kind of process, called demand-response, is essential in order to expand renewable energy, says Farid. Ultimately, the degree to which the power grid can accommodate renewable energy is limited by the need for reserve energy capacity. Shifting that capacity from conventional generation to buildings and household appliances can yield a grid that is less carbon-intensive and much more cost-effective.
Expanding this system through a market that includes commercial and residential users could essentially create a giant platform that would incentivize all users to give back power they are not using to stabilize the grid. Turning off the heating or cooling system in a building for half an hour might not change the internal temperature much, if at all—but if hundreds of buildings did that, it could make a huge difference in compensating for disruptions due to variability in wind or solar power.
At the same time, sharing that energy could be a source of revenue for companies. “All of a sudden my large building is something I could generate some real money with,” says Parker. “Those blowers and compressors that seemed like pure expense all have some spare capacity they could supply to the system.”
In the same way that Uber uses surge pricing to spur more drivers to hit the road at times of higher demand, the market could also vary prices by time and location. Parker explains that these are called locational marginal prices. As it stands, energy prices can vary dramatically across a geographical area. For example, in New York State, energy might be cheap upstate near the power plants but more expensive down in the city after you figure in the cost of transmitting it long distances and the relatively high cost of producing power in the city.
A market could subdivide those prices even more finely, for example, on a single street in Brooklyn, where prices could vary depending on how close you were to a substation. “The idea is to get prices as granular as possible,” says Parker, “so you could say exactly how much it is worth for a particular resource at this time in this place.”
Farid and Parker envision third-party vendors could monitor those changes, turning on and off equipment for hundreds of users according to demand. “They’ll say, we will trade on your behalf, and when we make you money, we’ll take a cut of that,” says Parker.
The same thing could happen for residential customers. “Third-party companies would come in and ask, if we help install this new technology in your home and save you $25 a month, would you give us $10?” Farid says.
With new smart appliances connected to the web through the “Internet of Things,” some of these functions could even be carried out automatically. “You could imagine your home thermostat or water heater would have a controller on it and sense changes in the grid in order to respond to price incentives,” says Farid. When, for example, energy prices go up due to a shortage, your thermostat could shut off and sell energy back to the grid for a set period of time, then switch back on again before the temperature falls below a certain level.
By the same token, a dishwasher could automatically run at 2 a.m. when demand is lower rather than at 7 p.m. when energy usage is at its peak, thus saving energy and saving a consumer money. “This type of measurement would empower consumers to make their own decisions about how and when they are going to use their energy,” Farid says.
Having more distributed energy sources could help make the grid more efficient in other ways as well. When a hurricane or an ice storm knocks out power lines in some areas, says Parker, the system could reroute energy around the point of failure rather than having to wait until the line to the power plant is restored. And it would also allow for construction of more alternative energy sources like wind and solar, leading to high-paying construction jobs.
“The evolution of electricity markets will provide so many win-win scenarios,” says Farid. “It has the potential to reduce energy costs for consumers, make the grid more reliable, bring about new jobs, and of course create the environmental benefits so many of us care about.”
While Parker and Farid haven’t actively collaborated yet, they are looking forward to combining Parker’s knowledge of platform markets and economics with Farid’s renewable energy and demand-response expertise to help make smart power grids a reality. “Geoff and I have very similar paradigms for where this is all going,” says Farid.
If there will be any pushback, Farid says, it will be from traditional energy companies that don’t diversify their energy offerings to include renewable energy and demand response services. But Farid and Parker both hope the positive benefits of saving energy and running a more efficient grid overall will outweigh any individual financial concerns. “Naturally, there are some energy stakeholders who would like us to consume energy as we always have,” says Farid. “But in terms of the benefit to the overall economy, the best megawatt is the one you don’t waste.”