What is renewable energy and why do we need it?
This article is part of the One Dish, One Spoon Series. If you haven’t read the first article on Decarbonization, you can do so here.
It’s the end of the work day. I hop into my car, put the key in the ignition, and make my way home. When I get there, I flip on the lights to the living room, the dining room, and the kitchen. Dinner tonight is salt and pepper tofu with rice, so I plug in the air fryer and the rice cooker. I turn on my bluetooth speaker and listen to music as I wait for dinner to be ready. The appliances beep and sing to tell me that they’re done. I plate everything and plop down on the couch in front of the TV to watch the newest episode of Abbott Elementary or Bob’s Burgers.
At every step of the way, I am using electricity. What is electricity? And where does it come from?
Figure 1: Jumping from atom to atom generates electricity from JRANK “All about Electricity”
Without diving deeper into physics—but if you want to, this video is great—we know that we use electricity to power our day-to-day activities. By the early 20th century, electricity stopped being a luxury item in wealthy homes and became an integral part of everyday life. Instead of using candles and whale oil lamps to provide light and wood-burning or coal-burning stoves to provide heat, homes and businesses began to rely on electricity.
HOW THE ELECTRICAL GRID WORKS
Electricity is a secondary energy source, which means we have to convert a primary energy source like coal or natural gas into electrical power. Power moves through a complex grid to reach our homes and businesses:
Power plants generate the electricity that is delivered to customers through transmission and distribution power lines. High-voltage transmission lines, such as those that hang between tall metal towers, carry electricity over long distances. Higher voltage electricity is more efficient and less expensive for long-distance electricity transmission. Lower voltage electricity is safer for use in homes and businesses. Transformers at substations increase (step up) or reduce (step down) voltages to adjust to the different stages of the journey from the power plant on long-distance transmission lines to distribution lines that carry electricity to homes and businesses (US Energy Information Administration).
Figure 2: Electricity generation, transmission, and distribution from U.S. Energy Information Administration.
Voltage is measured as current times resistance. Basically, voltage is how hard the grid is pushing electrons through, the current is how many electrons are flowing through, and resistance is the capacity to conduct electricity—larger, wider wires have greater capacity. Think of it like a straw: you can change the suction pressure through the straw, what is going through the straw, and how wide the straw is. Right now, the electrical grid is designed to have big load zones near power plants. These load zones have big “straws” and thus a large capacity for transmitting a lot of power.
As of 2023, 69% of our energy in the US comes from petroleum and natural gas. Power plants that generate electricity from fossil fuels burn fossil fuels on demand, as opposed to renewable energy like solar and wind which is harnessed along with natural cycles.
Figure 3: U.S. primary energy consumption by source, 2023
Burning fossil fuels not only emits carbon dioxide into the atmosphere but also sulfur dioxide, nitrous oxides, and particulate matter. Furthermore, it’s crucial to consider other environmental and health impacts of the fossil fuel industry. Underground coal mines can catch fire, collapse, and produce acid mine drainage, which makes the surrounding groundwater and soil toxic. Surface mining removes trees and overlaying soil and in the process destroys the ecosystem and makes the area prone to mudslides, landslides, and flashfloods. Likewise, drilling for oil and gas introduces chemicals into our water system that can cause cancer or other mutations and can severely damage our neurological, cardiovascular, endocrine, and immune systems. All of these extractive methods harm the fish, birds, and wildlife we rely on for healthy ecosystems. And there is so much more.
New England’s grid is currently designed for fossil fuel-based power plants. However, many of these power plants’ generation is at risk and many have closed or are retiring. As we transition away from fossil fuels, there is a grand opportunity to reuse the transmission infrastructure, or the big “straws”, and deliver clean energy to end users.
WHY WE ABSOLUTELY NEED RENEWABLE ENERGY
Renewable energy is energy derived from natural sources that are replenished on a human timescale. Fossil fuels are not limitless, and we will run out of coal, oil, and natural gas within the next 50-100 years. The transition to renewable energy is not a question of “if” but “when” and “how”. Rhode Island’s 2021 Act on Climate set mandates for emissions reductions, with the state reaching net-zero by 2050. In order to meet that goal, we will need to invest in multiple types of renewable energy. None of these renewables will be enough on its own to supply all of the energy we need, and each of these sources has its limitations.
The major sources of renewable energy are:
Solar energy from the sun
Wind energy from uneven heating of the sun
Geothermal energy from heat inside the earth
Hydropower from flowing water
Biomass from plants
To determine the environmental impact of different energy sources, experts developed a method called life-cycle assessment (LCA). LCA takes into account a product’s environmental impacts throughout its lifetime, from “cradle to grave”.
Figure 4: This graphic shows the life cycle phases of renewable energy technologies. Because renewable energy technologies like wind or solar do not produce emissions during use, most of their environmental impacts occur during construction before operations (upstream) and during decommissioning when the project is no longer in operation (downstream) operation. Graphic by Besiki Kazaishvili, NREL
GHG emissions are measured in grams of carbon dioxide equivalent per kilowatt hour (g CO2e/kWh). Carbon dioxide equivalent is a measure used to compare emissions of different greenhouse gases. According to COWI, an international consulting group with specialties in engineering and environmental science, this is approximately how much CO2e/kWh each type of power emits during its life cycle:
Figure 5: Carbon dioxide equivalent by source.
It’s clear to see that renewable energy sources have a much lower impact over the course of their lifetimes. And while the LCA method isn’t perfect, it brings attention to the less obvious costs and benefits of renewable energy technologies. For example, you may have driven by a solar farm on the side of a highway, but did they need to clear a forested area to install it? It seems counterintuitive to chop down a forest, which itself absorbs carbon emissions, to install solar panels.
Figure 6: Clean energy technical potential in New England, Brattle Group, 2019.
Along with life cycle concerns and health factors, we also need to consider:
Suitability – What type of renewable energy is available in the region? Solar energy is relatively cheap and effective, but it doesn’t work as well in the winter months in New England, which have more cloudy days and fewer hours of daylight. But Southern New England does have an abundance of offshore wind energy that perfectly complements solar, producing the most energy during the winter months and at night when the sun isn’t shining.
Cost to ratepayers – In 2023, Rhode Island generated 87% of its electricity from natural gas, and as your energy bill in the winter might hint, the cost of natural gas is volatile. Fossil fuel prices are hard to predict because weather impacts demand, and how much natural gas is produced or imported fluctuates. Although renewable energy will stabilize prices, there may be increased costs upfront depending on the comparative price of fossil fuels. It’s important that the cost is equitably distributed among ratepayers, especially low-income families who already carry a higher energy burden.
Just Transition – This transition to clean energy is an enormous opportunity to return economic and democratic power back to communities. Once renewable energy technologies are in operation, we must protect tenants and frontline communities so that they are not pushed out of their homes and neighborhoods. We also need to ensure energy workers who are affected by the transition have a clear pathway to jobs with family-sustaining wages.
In February 2021, Texas’ power grid failed in one of the United States’ worst energy crises. As Winter Storm Uri pushed temperatures lower and lower, demand for electricity surged and ultimately led to a fuel supply shortage. This power outage lasted many days and cost some people their lives. While Texas has a unique approach to energy regulation, the potential of grid failures becomes greater as climate change strains our existing systems—changing weather patterns increase the need for heating and cooling and extreme weather events put pressure on our infrastructure. In addition to modernizing the grid, investing in microgrids, and incentivizing battery storage for buildings, we need to find ways to meet demands for electricity that do not further contribute to GHG emissions.
Building new infrastructure for renewable energy will be a long and expensive process, but not doing so will be the most costly option of all. In addition to meeting demands for electricity with clean energy, the other half of the equation is examining those demands in the first place. Strategies for increasing energy efficiency—such as proper insulation, a well-sealed home with updated windows, energy efficient appliances, and LED lightbulbs—can help drive down energy demand. However, we know the best way to conserve energy is, when possible, to not use it at all: shutting off lights we’re not using, running electronics and appliances only when we need them, and carpooling, taking the bus, biking, and walking when possible. As One Dish One Spoon reminds us, we all share the gifts of the earth and thus the responsibility to give back is ours as well.
