Low Carbon Energy

Thanks to the Clean Energy Resource Teams for the photo!

As mentioned elsewhere on this site, low carbon energy systems are Priority 3, meaning they must be accompanied by a strong commitment to improving behavior and energy efficiency of buildings. Otherwise, we will simply be putting low carbon energy into a sieve.


But if you are on this page, we assume you have already made that commitment. So let's begin taking steps towards low carbon energy for our properties, or perhaps to support electric vehicle recharging stations.

At CCR, we believe that decarbonising the state or national grid is best left to the professionals at the utilities. Therefore the projects we support are at community scale such as a city, neighborhood or even individual residential and business complexes. Those projects might focus on solar, wind or a district heating and cooling system, preferably with the capacity to store excess energy. All of these have the potential to reach a target of 15 grams of carbon dioxide per kWh (kilowatt-hour) or below if implemented properly. And they are all cost-effective, but only if careful thought is given to balancing supply and demand (so you do not produce too much or too little energy), aggregating small scale projects (to obtain reasonable finance terms), ensuring large buy-in from potential consumers of the energy (the per person costs of energy decrease as the size of the consumer base increases), and how you will attract consumers to leave the protective arms of the local utility and rely on a community system. 

Community energy systems (known sometimes as Community Choice Energy or Community Energy Aggregation) offer the potential to decrease the carbon intensity of energy consumption compared to the grid. Just bear in mind that in both California and the UK, the carbon intensity of that grid has been decreasing significantly as more and more renewables are brought on line. Still, the grid is unlikely to reach the carbon intensity you can achieve with a bespoke community energy system with solar or wind, in part because the grid needs to supply large scale industrial users of power, users who find it more difficult to rely solely on renewables (although this limitation is being eased as we speak). And even if the grid intensity decreases, there is still an advantage to owning your own system to control rate increases and to invest in local businesses that can build and maintain your system.

Are low carbon energy systems financially viable? Undoubtedly at utility scale. As our Financing the Future of Energy report showed, in 2015 more than half of the global new generation capacity for electricity was from low carbon sources. The Energy Information Administration has projected that in the US, this percentage will rise to 70% in 2020 (see the bar chart to the left). Just keep in mind that three quarters of this new investment is due to utility scale projects, which attract substantial investment due to the stability and reliability of utilities. But a quarter is due to rooftop solar, with California being the second largest concentration in the nation after Texas.  So there is clearly a large and growing business case to be made for low carbon community energy systems.

Emissions from renewables

Renewables are not free of carbon emissions. There is carbon dioxide released during their manufacture. With current manufacturing processes, the best we could hope for is to have our electricity grid carbon intensity decrease by another factor of 2.

But as manufacturing systems also decarbonise, this 'embodied carbon' will drop. A recent study in Nature Energy looks at embodied carbon out to 2050, with a large decarbonization of the global economy. It finds that "each kilowatt hour of electricity generated over the lifetime of a nuclear plant has an emissions footprint of 4 grammes of CO2 equivalent (gCO2e/kWh). The footprint of solar comes in at 6 gCO2e/kWh and wind is also 4gCO2e/kWh. In contrast, coal CCS (109g), gas CCS (78g), hydro (97g) and bioenergy (98g) have relatively high emissions, compared to a global average target for a 2C world of 15 gCO2e/kWh in 2050."
However, a note of caution: Do not expect your community system to produce energy at much less than the unit cost (cost per kWh consumed) of the grid. Even the best systems we have seen at CCR just about break even compared to the grid in California. It is essential that you build a very strong business case first since your costs per unit of energy will depend critically on the number of consumers who join the system, the interest rates you can negotiate, the availability of government grants, the cost of maintaining the system, the costs to distribute that energy once it is generated, the costs to remain connected to the grid just in case your energy system goes down, and so on. It is likely that your case for moving forward will rest more on the pride of ownership and the reduction in carbon intensity than on dramatic cost savings. 

In the projects we have seen fail, the main reason has been a unit cost of energy that ends up being higher than that of the grid (and higher than that promised), a failure to maintain the system adequately so outages become frequent, or incomplete backup by the grid so there is no energy available to the consumer when the system goes down (however temporarily). Plan, plan, plan! All of these reasons for failures can be avoided, but not without attention to details. Community enthusiasm may help a project get traction, but success depends on some hard-nosed, professional analyses.

Pay particular attention to load leveling. Successful community systems have a mix of different kinds of consumers, using energy at different times of the day. If you have everyone trying to draw energy at the same time, you run the risk of having insufficient energy to go around. And if they all stop using energy at the same time, you run the risk of needing to 'shed' energy that is being generated, unless you develop energy storage (which can be a costly addition to your system). With a mix of users, this 'energy load' becomes flat, which is ideal for a community energy system. Again, the solution is often to remain connected to the grid, drawing on that when needed and putting your excess power back into that grid. But this requires professional negotiations with the utilities that operate the grid.


Do you still need to consider behavioural change? Go to the Low Carbon Behaviour part of the CCR site.

And if you are considering a energy efficiency in a property, go to the Low Carbon Buildings part of the CCR site.