How Do Energy Efficiency And Renewable Energy Sources Work Together?

As the world faces the interlocking challenges of climate change and energy security, energy efficiency and renewable energy have emerged as two critical solutions. Both strategies help reduce greenhouse gas emissions from fossil fuel combustion while also decreasing dependence on finite resources like coal, oil and natural gas. Energy efficiency refers to using less energy to provide the same service, like insulation to reduce heating and cooling needs. Renewable energy utilizes naturally replenished sources like sunlight, wind, water and geothermal heat. Together, these complementary approaches can cost-effectively transition our energy system to be cleaner, more secure and more affordable.

The U.S. Department of Energy explains that “Energy efficiency saves money, increases the resilience and reliability of the electric grid, and provides environmental, community, and health benefits.” https://www.energy.gov/eere/energy-efficiency-buildings-and-industry

Table of Contents

Energy Efficiency

Energy efficiency refers to using less energy to provide the same service.Energy efficiency can be achieved through equipment, technology, processes or behaviors that reduce energy use while maintaining or improving performance. Some examples of energy efficiency measures include:

Insulation – Adding insulation to walls, attics and foundations reduces heat loss, improving efficiency of heating and cooling systems.
LED lighting – LED bulbs use at least 75% less energy and last up to 25 times longer than incandescent lighting.

Efficient appliances – Appliances like refrigerators, dishwashers, washing machines and dryers that have earned the ENERGY STAR rating use 10–50% less energy and water than standard models.

Other energy efficiency measures involve improved operations and maintenance, smart building controls, and efficient system design. Overall, energy efficiency lowers energy costs and reduces environmental impacts.Energy efficiency brings economic, environmental and security benefits such as reducing energy bills, lowering greenhouse gas emissions and reliance on imported energy.

Renewable Energy

Renewable energy comes from natural sources that are constantly replenished, such as sunlight, wind, water, and geothermal heat. According to the U.S. Department of Energy, renewable energy is defined as “energy from sources that are naturally replenishing but flow-limited; renewable resources are virtually inexhaustible in duration but limited in the amount of energy that is available per unit of time” (https://www.energy.gov/eere/renewable-energy).

The major types of renewable energy sources include:

Solar energy from the sun, which can be converted into electricity via solar photovoltaic panels or concentrated and used to heat water or indoor spaces.
Wind energy captured through wind turbines that generate electricity.

Hydropower from flowing water, such as dams, that is used to generate electricity.
Geothermal energy from heat inside the earth that is extracted to generate electricity or provide heating/cooling.
Bioenergy from organic plant and animal waste, which can be used to produce electricity, transportation fuels, and heat.

Renewable sources provide around 11% of primary energy use worldwide. The fastest growing renewables are solar and wind energy, which increased by over 60% between 2009 and 2019 (https://www.nrel.gov/docs/fy01osti/27955.pdf). Renewables have the potential to meet rising energy demand in a sustainable way, while reducing dependence on fossil fuels and mitigating climate change.

Complementary Nature

Energy efficiency and renewable energy sources work together in a complementary way to reduce environmental impact and meet energy needs (REN21, 2020). Energy efficiency reduces energy demand by enabling the delivery of more services for the same energy input, or the same amount of services for less energy input (Energy5, 2022). Common efficiency measures include insulation, energy-efficient appliances, lighting upgrades, and smart thermostats. Renewable energy increases the supply of clean energy by harnessing naturally replenished sources like solar, wind, hydro, and geothermal (Ding Energy, 2024).

Together, efficiency and renewables lower fossil fuel consumption and carbon emissions. Efficiency reduces the amount of energy required, while renewables provide clean sources to meet the reduced demand. This integrated approach accelerates the transition to a more sustainable energy system.

Energy Efficiency Enables Renewables

Reducing energy waste through efficiency makes it easier to meet demand with renewable energy sources like solar and wind. Energy efficiency improvements like weatherization, upgrading appliances, and switching to LED lighting reduce overall energy consumption, allowing a larger share of demand to be met by renewables (EPA). With lower energy usage, the variable nature of renewables becomes less of an issue. The International Renewable Energy Agency found that “improved efficiency reduces total energy demand, allowing the share of renewables in the energy mix to grow faster” (IRENA). Energy efficiency makes the transition to renewables smoother and more cost effective.

Renewables Need Efficiency

One of the main challenges with renewable energy sources like solar and wind is their inherent intermittency. The sun doesn’t always shine and the wind doesn’t always blow when energy is needed. This intermittency means that any energy generated when it’s not needed is essentially wasted if it cannot be stored or used elsewhere in the grid (https://energy5.com/the-potential-of-energy-efficient-technologies-in-renewable-energy-integration).

Energy efficiency plays a crucial role here by reducing overall energy demand and waste. With high efficiency appliances, lighting, HVAC systems, and building materials, the periods of renewable energy shortfall are minimized. Efficiency enables better grid integration and utilization of renewables by reducing the gap between renewable generation and energy demand (https://utilitiesone.com/maximizing-energy-efficiency-the-integration-of-renewable-energy-systems-in-prefab-and-modular-construction).

Policies that encourage energy efficiency can support higher renewable energy penetration without sacrificing grid reliability. Efficiency reduces the risk of blackouts and improves resiliency when relying heavily on renewables (https://www.sciencedirect.com/science/article/abs/pii/S0301421519305099). In essence, energy efficiency and conservation provide a foundation that enables renewable energy to scale.

Energy Storage

Energy storage plays a crucial role in enabling greater use of renewable energy sources like solar and wind. This is because renewables are inherently intermittent – the sun doesn’t always shine and the wind doesn’t always blow when energy is needed. Energy storage provides a way to capture excess renewable energy when it’s generated and discharge it when required (1).

There are a variety of energy storage technologies, including batteries, pumped hydro, compressed air, flywheels, and thermal storage. Lithium-ion batteries in particular are becoming a popular choice for grid-connected storage due to declining costs and versatility (2). Pairing storage with renewable energy sources can provide firm capacity, frequency regulation, load following, voltage support, and black start capabilities (3).

Storage also enhances energy efficiency. By storing energy when demand is low and discharging when demand is high, storage flattens the load profile which allows generation assets to operate more consistently and efficiently. Further, storage reduces the need to ramp up and down conventional fossil fuel plants to meet peaks. Overall, energy storage enables greater renewable energy integration and grid efficiency.

Smart Grids

Smart grids utilize two-way communication technology, advanced monitoring and control systems, as well as automation to help efficiently balance energy supply and demand. These upgraded grids can precisely match electricity generation with usage in real-time across the grid network (1). This capability allows smart grids to better integrate intermittent renewable energy sources like solar and wind while maximizing energy efficiency. For example, smart meters provide consumers with real-time feedback on energy usage, allowing them to adjust habits to minimize waste. Utilities can also use dynamic pricing to incentivize reductions in peak demand, shifting more consumption to times when renewables are abundantly generating energy.

In addition, smart grids collect data to support forecasting, prediction and response systems. This helps grid operators prepare for variability in renewable generation, preemptively adjusting other sources or reducing demand when needed. Energy storage systems can also be coordinated by smart grids to store excess renewable energy for later use. Overall, smart grid technologies enable the dynamic balancing of supply and demand that allows for large-scale integration of renewables while maintaining reliability and maximizing energy efficiency (2).

Sources:

(1) https://innovationatwork.ieee.org/smart-grid-transforming-renewable-energy/

(2) https://www.nrel.gov/docs/fy15osti/63919.pdf

Policies

Government policies and regulations play an important role in promoting energy efficiency and renewable energy adoption. These policies provide incentives, standards, and regulations that help drive implementation of technologies and projects that reduce energy consumption, increase efficiency, and expand renewable energy usage.

Key policies that support both energy efficiency and renewables include tax credits like the Investment Tax Credit (ITC) and Production Tax Credit (PTC), which provide financial incentives for deploying renewable energy systems and implementing energy efficiency improvements. The ITC offers a tax credit for installing renewable energy systems like solar panels, while the PTC provides a tax credit per kilowatt-hour generated by certain renewable sources. Energy efficiency tax deductions are also available.

Appliance and equipment energy efficiency standards set minimum requirements for energy performance of common products like lightbulbs, air conditioners, and computers. Building energy codes and standards like ASHRAE 90.1 also set baseline energy efficiency requirements for new construction and renovations. These standards drive adoption of high-efficiency technologies and building designs.

Renewable portfolio standards require utilities to source a certain percentage of their electricity from renewable sources. These standards create guaranteed demand for renewable energy and help drive development of sources like wind and solar. State renewable energy goals also set targets for renewable energy growth.

Conclusion

Together, energy efficiency and renewable energy are the foundation of a sustainable energy future. While they have distinct benefits, energy efficiency and renewables reinforce each other in key areas. Energy efficiency reduces demand, allowing more rapid growth of renewable energy. Efficiency reduces excess generation needs from renewables. Both provide emissions reductions. Smart grid technologies and new policies will enable deeper penetration of efficiency and renewables. Working together, energy efficiency and renewables present a powerful and strategic path forward, enabling us to reduce energy waste and shift towards cleaner, more sustainable sources of energy.

To unlock the full environmental and economic benefits of clean energy, policymakers and planners should accelerate efficiency improvements while scaling up renewables simultaneously. While ambitious, this approach represents an achievable vision for communities seeking affordable, reliable and low-carbon energy solutions.