Greenwashing or The Truth: Chicago’s 100% Renewable Energy Milestone Explained

On January 3, 2025, the City of Chicago announced that it is now powering all city-owned buildings with 100% renewable energy sources, including facilities like the O’Hare and Midway Airports and the Harold Washington Library. The initiative will reduce Chicago’s carbon emissions by 290,000 metric tons annually, or the equivalent of removing 62,000 cars from the road.

Where the energy comes from: The city stipulated that 70% of the renewable energy generation is powered by the Double Black Diamond solar project in Southern Illinois, with the other 30% is procured by something called renewable energy credits (RECs).

Chicago is the first of the United States’ major cities to lay claim to this achievement, but how much of it is real progress, and how much of it is what many might consider greenwashing? This article explores the exact meaning behind Chicago’s 100% renewable energy figure and what this means for the future of Chicago’s sustainability objectives.

Is all of Chicago being powered by renewables?

Not if you consider the Chicago Metropolitan Area, which includes all of Chicago’s neighborhoods and surrounding suburbs. The City of Chicago’s claim to 100% renewable energy applies to the city’s 400+ municipal buildings, or those under the jurisdiction of the local government. So Chicago’s 7,000+ restaurants and 1.2 million housing units are not a part of the city’s renewable energy transition, just facilities like libraries, police stations, and city hall.

Where is Chicago getting the renewable energy from?

70% of the energy powering Chicago’s municipal buildings is coming from the Double Black Diamond Solar farm in central Illinois. The solar project began in 2017 under former Chicago Mayor Rahm Emanuel, and each mayor since has collaborated with local project developers and energy suppliers to strike a deal where about half of the solar project’s energy output would be purchased by the city.

The relationship with Double Black Diamond Solar, as outlined in the official press release, brings more than just environmental benefits to Chicago and Illinois residents. The outlook also favors the economy and job market, offering work opportunities during the construction of the project and engaging organizations like Chicago Women in Trades to offer free job training to women in construction and welding.

As far as the environmental benefits, however, the idea that 70% of Chicago’s facilities are directly powered by renewable energy can be misleading to those unfamiliar with the energy market. The energy from Double Black Diamond Solar is not input directly into the city, per se, but acquired through something known as a Power Purchase Agreement.

What is a Power Purchase Agreement (PPA)?

PPAs, as the name implies, are financial agreements between a customer and energy supplier. For an agreed upon period at a fixed price, the customer will purchase the electric output of the solar farm while the project developer handles operations and maintenance. The PPA structure is very common with solar customers, even on a residential scale.

Why PPAs are beneficial: price fluctuations in the energy market happen very frequently, which can pose risks for customers and energy suppliers alike. By entering a PPA structure, customers - in this case the City of Chicago - can incur cost savings compared to traditional utility rates, and not have to pay upfront capital costs to start experiencing the benefits of the renewable energy project.

What PPAs don’t do: because PPAs are just a financial agreement, no electric generation is being physically redirected to Chicago. The power is just delivered to the broad electric grid and is sent wherever there is demand. It is impossible to tell if the lights in Chicago, at any given time, are being powered by renewable energy, as all energy after it’s generated works the exact same.

What’s the alternative to a PPA? Realistically, PPAs are the only way large cities and corporations are able to lay claim to the power generation of utility-scale energy projects. Our electricity grid is not sophisticated enough, nor would it be structurally efficient, to direct power from a specific energy source to a specific location. The only way the City of Chicago could lay claim over the physical delivery of renewable energy to its facilities would be if all buildings had rooftop solar installed.

The bottom line: To the extent that PPAs financially support the operations and maintenance of clean energy projects and enable clean energy to be delivered to the electric grid, Chicago is doing its part to reduce 70% of its carbon emissions.

The other 30%: how do Renewable Energy Credits (RECs) work?

RECs are not a direct purchase of energy, but rather a certificate giving legal claim to the power generated by a renewable energy source.

The benefit of RECs: RECs can act as a signal to the energy market for increased demand for renewable energy projects. For businesses and other institutions, the main benefit of RECs is they offer the legal ability to claim their power is sourced from renewables.

What RECs don’t do: Unlike PPAs, renewable energy credits have nothing to do with new renewable power being added to the grid. For every megawatt of power that is added to a utility company’s generation capacity through clean energy projects, an REC is created for purchase. Therefore, having an REC is a claim to clean energy that is already part of the grid, and does not contribute to reduced carbon emissions.

The bottom line: RECs can be controversial because they allow entities to say they are powered by renewables, but they do not physically receive renewable energy nor does the purchase help to actually decarbonize the grid. No renewable energy is generated or financed by the purchase of RECs.

So, is Chicago really powered by 100% renewable energy?

In the ways that count, not entirely. Only the municipal buildings under the City of Chicago’s jurisdiction, of which there are about 400, are included. And 30% of that energy is not energy at all, but a collection of RECs that allow the city to legally claim it is powered by renewable energy.

What’s important to remember: The electric grid is vastly interconnected, and once power is added to it you can no longer tell what kind of generation project the electricity was sourced from. So even though Chicago cannot say it is physically powered by just renewables, it can claim the next closest thing, which is that 70% of its energy consumption is covered by the purchase of power generated by the Double Black Diamond Solar project.

There’s still work to do: Angela Tovar, Chicago’s Chief Sustainability Officer, has acknowledged that RECs are not the endgame to Chicago being powered by 100% renewable energy. With a goal to be carbon-free by 2035, Tovar hopes that the purchases will encourage local renewable energy development and allow the city to bridge the REC gap.

Other resources: To learn more about what the City of Chicago is doing to reduce their carbon footprint and get involved yourself, check out their energy efficiency and renewable energy page.