18th March 2019

Carbon content of heat CA

Heat in CA

At Erda we believe in measuring the output of carbon emissions produced by our Geo-exchange technology. On our Erda Insights page you can view the live carbon emission data from an Erda system compared to other energy systems at any point in time. We can gain insight through comparing different electrical grid data from specific locations to see how our technology could operate compared to existing heating technologies.

When most think of California, they think of the busy city of Los Angeles, the beautiful beaches in So. Cal, or maybe the iconic Golden Gate Bridge located in San Francisco. While most are familiar with these spots being in warm or temperate climates, most are unaware of the remaining State’s diverse temperatures that swing a considerable amount over the State’s 423,970 sq. km’s. Temperatures in Northern California can drop into the negatives (F) while in the “Valley” temperatures can often stay above 100 degrees (F) for days to weeks at a time.

With a diverse climate stretching throughout California, its important to have appropriate heating and cooling technologies to meet the demand in each location while also keeping its growing population of nearly 40 million people comfortable and safe.

CCH in the US

We wanted to look back at the carbon content for the electrical grid (CAISO) in CA to see how using Erda’s technology in that grid might compare to existing heating technologies. To do this, we gathered real time carbon data for the CA electricity grid – we obtained this data from electricityMap in 5-minute intervals.

The net thermal energy output by Erda systems and the net electrical consumption used by our systems was gathered from our Erda | smart™ platform to determine what the carbon content of our heat could be. We compared these emissions of the Erda system to other technologies. Read more about the methodology we use to calculate the CCH at Erda here.

These CCH values can then be compared over the past few years to help us to see the trends in the CCH of different fuel sources in CA.  Insights into these trends can help determine the best possible solutions for the state to meet their carbon reduction and clean energy goals.


The graph below displays the CCH in California over the last four years, beginning in April of 2014. Carbon content of the electrical grid is represented by the yellow line (which you can see has had a steady downward trend over the past few years). In contrast to this the CHP machine’s CCH (shown in grey) has had a steady trend upward over the past few years – and as the grid continues to get cleaner, the carbon intensity of the CHP systems will increase as the machine is no longer off setting its emissions with clean electricity.  In September 2016 the carbon content of the grid begins to consistently trend lower than that of CHP.

                                                                                                                                                                       Fig. 1 CCH CA

The solid grey line represents the carbon content of natural gas. According to the EIA , nearly two-thirds of home in CA are currently using NG to heat their homes. With the carbon content of the grid quickly trending downward, it won’t be long before the carbon content of the electricity grid consistently drops below 184 gCO2/kWh, making electrification of heat the cleanest way of heating buildings.

Much below any of these lines is the green line which represents the CCH for Erda’s technology. Erda’s geo-exchange technology’s only primary fuel source is energy from the electrical grid (in this case CA’s). Because of this, Erda’s technology will only become cleaner as the grid continues to green.

As shown, when the amount of overall grid carbon decreases, the CCH of the CHP system increases. This is concerning for the future of CHP, as we look to “green” our energy and heat buildings with low carbon fuel sources. Edra’s technology however will be the best choice when looking to do this. Natural gas, one of the most common ways we heat our homes and building shows a higher carbon content than the CA grid at certain times, showing that it might not be the answer for a low carbon future either. With CA grid carbon content rapidly trending downwards, it won’t be long until NG as a fuel source is no longer viewed as “clean”.

Electrification of heat

Edra’s technology allows for safe reliable heating and cooling with low carbon emissions. The technology uses a combination of heat pumps and electricity from the grid to heat and cool buildings.

California has the second highest carbon emissions in the country – heating and cooling currently are major contributors to this. To drive these emissions down it is clear that electrifying heat through geo-exchange technology will be necessary to help states meet targets and regulations.

Two-thirds of California households use natural gas to heat their homes, causing the state to use the second highest amount in the entire US according to the EIA. The use of NG in the state has led to many disasters over the years.

Since 2017 alone Cal fire has blamed Pacific Gas and Electric company (PG&E), for 12 of the devastating fires that have tragically occurred in California reports the Sacramento Bee. These reoccurring fires have left people homeless and without loved ones. By eliminating the use of NG through heat pump technologies such as Erda’s geo-exchange, the risks of these events reoccurring could be taken away.

While NG is one energy concern for the state, the biggest challenge that renewable energy is facing is happening in CA – the “duck curve”. Solar production has been rapidly increasing since 2010 causing a drop-in energy demand during the day time but once the sun sets, there is a peak, causing power plants to quickly start up to meet this demand- which then causes a massive strain on grids and transmission lines.

 The Synapse Energy Economics report that if done right, electrifying heat in CA could cause a decrease in natural gas consumption by one-third while adding to the states overall electricity consumption by 19%.Our geo-exchange technology can operate during off peak times to reduce the strain on the grid. Less electricity will be needed for Erda systems during peak times causing the curve to flatten and balance out.

While California is also facing a major water scarcity crisis, Erda’s geo-exchange technology allows for a major reduction in water as there is no demand for water, which is required in most cooling technologies. According to the EIA 31% of CA’s energy use goes toward space heating and cooling. Using our technology, we could both help balance out the duck curve and help decrease water use by driving down CA’s energy consumption through geo-exchange.

The state has set a 100% clean (carbon free) electricity target by 2045 while meeting two milestone targets on the way to achieving it, 50% renewables by 2026 and 75% renewables by 2030, according to the SSB 100. Along with these targets they have an 80% reduction in 1990 CO2 levels by 2050. To meet these goals, it is crucial for CA to first green its electric grid and then rely on heat pump technology such as Erda’s geo-exchange to electrify heating and cooling in buildings.

With states looking for low carbon heating and cooling options, electrifying heat through heat pumps is the best option. States are currently investing money into R&D of heat pump technology, however Erda has proven success over the past seven years of its technology operating in the UK. At Erda we have the expertise to operate our systems in a smart way helping to cut carbon, cost, and energy.

Rachel Feeney
Erda Energy Analyst

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