Reducing the Strain on the Power Grid

Microgrids Are Proliferating and Some Are Incorporating EV Batteries

Renewables are the fastest-growing form of power generation. Moreover, they are the only source of power keeping pace with the expanding demand for electricity as we adopt electric vehicles (EVs) and all-electric buildings. The disconnect that the experts worry about falls on the grid due to the wild fluctuations between supply and demand. Despite ongoing repairs and upgrades, there has been virtually no grid expansion of capacity over the past decades. Change is coming rapidly, however.

Technology is transforming the large batteries in EVs, trucks, and buses into versatile assets. These components are beginning to store excess renewable electricity and make it available for demand spikes. Millions of EVs can be thought of as a huge energy system that can be connected to another huge energy system, the electrical grid. There has been talk about this for years, but we are now seeing tangible results.

In part because of the war in Ukraine and the resulting boycott of natural gas from Russia, Europe is moving rapidly to create microgrids that combine renewable generation with large battery storage and bidirectional flows for large numbers of EVs. Utrecht in the Netherlands is considered the largest bidirectional city. One of their projects is a parking facility, covered by 2,100 solar panels that provide power to 450 bidirectional charging stations and next-door buildings. The city is planning for 10,000 bidirectional EVs, 10 percent of their total.

There are many advantages to this combination beyond the free parking that bidirectional cars receive when plugged in. By connecting EVs to the grid, utilities need less reserve capacity on hand for peak periods. Utility costs are reduced, and car owners can save up to 50 percent on electric bills. For energy purveyors, the price of electricity changes from minute to minute as supply and demand surge or ebb. Those managing bidirectional systems buy power when solar and wind power are abundant and cheap, store it in electric vehicles, and sell it when demand and prices climb. It’s an old business strategy — buy low, sell high.

Ford, GM, BMW, Mercedes-Benz, and Renault are currently selling EVs with two-way charging software. All EV manufacturers are planning bidirectional cars by 2026. To underline the potency of this approach, California has 70 gigawatts of storage in all the EVs on our roads. In comparison, the total battery storage in all our homes and buildings is only 2-3 gigawatts.

When EV stored power is given back to buildings or the grid, the amount is small and limited by the bidirectional software, or by the decision of the EV owner. Typically, the giveback is equivalent to 10 miles, while keeping enough stored for at least an 80-mile range. However, many EVs giving back, each one only a little, adds up to damping supply and demand swings and big savings to customers and utilities. This approach is also an important tool in countering climate change.

The Big Picture on Electric Vehicles

Fewer Vehicles and Driving Fewer Miles Needs to Be Our Future

The world is rapidly moving toward electric mobility — bikes, scooters, cars, buses, and trucks. New rules proposed by the Federal Environmental Protection Agency (EPA) for more rigorous tailpipe pollution reduction means that within 10 years, two-thirds of all new cars, half of new commercial vehicles, and up to a third of new 18-wheelers could be electric. California has set new standards that require manufacturers to sell an increasing number of zero-emission freight trucks and buses.

These moves are momentous in tackling the 28 percent of total U.S. climate pollution that comes from transportation. The truck and bus component represents about one-tenth of all U.S. vehicle traffic but accounts for more than half the sector’s air pollution.

A word of caution, however. The fossil-fuel industry, in spite of its public statements supporting clean energy and its massive spending on messaging, sends more lobbyists than any country to every national or international meeting on climate for the purpose of slowing or disrupting progress toward a cleaner energy future. Moreover, it collects $5.2 trillion in subsidies annually (6.5 percent of global GDP) and continues to develop every opportunity to extract more fossil fuel.

Clearly, this pattern of extraction and exploitation must change if the planet is to be saved. Furthermore, cutting back on the amount of energy produced, including renewable energy, will make the transition to 100 percent renewables easier and faster to accomplish. The exception is in the lowest-income countries that need to increase energy use to meet basic human needs. The IPCC (Intergovernmental Panel on Climate Change) indicates that if we want to limit warming to around 1.5 degrees Celsius above pre-industrial levels, then we need to scale down global energy use, mostly in high-income countries. Why in rich countries? Because on average, we consume 28 tons of material stuff per person per year. Focusing on materials has a range of powerful benefits, including taking pressure off ecosystems. It means less deforestation, less habitat destruction, and less biodiversity collapse.

The framework for thinking about electric cars and trucks should include reducing the total number of cars, making them smaller, and reducing miles driven. The best way to achieve this scaling back is to invest in affordable (or even free) public transportation, which is more efficient in terms of materials and energy. Making it as attractive, clean, and convenient as possible is essential.

While sunshine and wind are obviously clean, the infrastructure we need to capture them and the products that use this clean energy are not. Transitioning to them is going to require dramatic increases in extraction of metals and rare-earth minerals with real ecological and social costs. We have deluded ourselves (or been deluded) many times by new technologies or material efficiencies that promise sustainable gains yet lead to more production, consumption, and greenhouse gases. Only by universally applying a net green analysis, which looks at the entire picture and focuses squarely on environmental impact reduction, will we help ourselves and our planet.

Heat Pumps Are Becoming a Part of Our Future

Lower-Income Families Can Now Have Better Health, Reduced Utility Bills, and More Comfort

Nearly half of residential buildings in the U.S. were constructed before 1973, when building code energy standards were virtually nonexistent. As a result, most homes and residential buildings still rely on old technologies for heating and cooling: furnaces and boilers for heating and big rooftop air conditioning units for cooling.

Heat pumps, however, are gaining traction. The same piece of equipment can provide heating and cooling. Heat pumps are powered by electricity but have efficiencies 3-5 times that of fossil-fuel heating systems. Despite the name, heat pumps do not generate heat; they move it from one place to another. In heating mode, they absorb latent heat energy from the outside air, even cold air, and transfer this heat to indoor air. The condenser and evaporative coil, which are located outdoors, use a liquid called a refrigerant to soak up heat and move it indoors or capture it indoors and release it outside, depending on where heat or coolness is needed. The source of thermal energy for a heat pump can be the air (an air-source heat pump) or the ground (a ground-source heat pump). 

Refrigerators are heat pumps but with the condenser located at the back or bottom of the appliance. We feel heat around a refrigerator because it is pulling heat out of the cold air inside the unit, thereby making it even cooler. A big plus that heat pumps offer is improved indoor air quality because there is no combustion.

There are also heat-pump water heaters and heat-pump clothes washers and dryers. Efforts are underway to create a household system where one compressor placed outside can power these various heat-pump services. 

It has been known for decades that saving energy is cheaper than creating fossil-fuel energy. Investing in such efficiencies has among the best return-on-investment. In 2021, Americans spent an average of $1,380 per year on energy bills. Installing efficient windows; preventing air leaks; insulating roofs, attics, crawlspaces and walls; and changing existing lighting to LEDs, together with investing in heat pumps, can cut utility bills by more than half.

The Inflation Reduction Act that President Biden signed into law last August invests $369 billion in climate reducing strategies over the next decade — a big part of which will go for energy retrofits and electrification of homes for moderate-income and disadvantaged families. The many jobs created by doing these retrofits and improvements will be local and primarily benefit small companies. 

If buildings around the globe are electrified and the sources of that electricity are from renewables, by 2050, one-sixth of the world’s total greenhouse-gas emissions would be eliminated.

The Battery Storage Challenge Is Being Solved

Researchers Are Using Less Costly, More Abundant, and Environmentally Benign Materials in Battery Innovation

Using electricity rather than fossil fuels to power our world offers many pluses, especially since electricity is increasingly being produced from the sun, wind, ocean currents and tides. Microgrids and sophisticated software monitoring power needs and providing instantaneous switching are making communities even less dependent on fossil fuels for peak demand periods. Battery storage is the key component that will enable us to get to 100 percent clean electricity. One of the biggest obstacles in this trajectory is the limited, costly, and environmentally damaging mining of lithium, nickel, and cobalt — all of which are used in the manufacture of batteries.

A lot of research is going into making batteries using other, more abundant materials with fewer of the drawbacks of current batteries, namely, flammability and spiky dendrites. The spikes are caused when batteries are charged too quickly and result in shortening the battery’s life.

One international team is getting results using aluminum as one of the electrodes and sulfur as the other with a common salt as the electrolyte. The 230-degree Fahrenheit temperature required to melt the salt and run the battery can be generated internally by normal charging and discharging cycles — charging from the sun during daylight and discharging after dark when electricity is needed. The scientists estimate that the cost will be 12-16 percent of today’s lithium-ion batteries.

In Finland, a functioning sand battery seems to solve the problem of year-round green energy for heat. It works by heating sand (100 tonnes) in an insulated silo using electric-resistant heat produced from surplus wind and solar energy. The sand heats up to almost 1,000 degrees Fahrenheit and maintains this temperature for months until demand and energy prices are high. When needed, air flows through a heat exchanger in the sand to extract the heat for use in a district (neighborhood) heating system or for industries that use a lot of heat like food and beverage processing. The town of Kankaanpää is using the first commercial installation of a sand battery.

Researchers at the University of Cambridge have developed a battery system with a non-toxic form of blue-green algae (Synechocystis) that takes in solar energy by photosynthesis. They have used it to power a microprocessor of a computer for more than six months. It is biologically based, produces renewable energy, and multiplies naturally, making it easily scalable. The device does not require any inputs other than sunlight.

Another solution gaining traction is to produce hydrogen from excess renewable electricity and store it until electricity demand is high and renewable generation low.

These are a few of the storage innovations that are likely to be part of the ensemble of processes that get us to our mid-century, carbon-neutrality goal.