Informed energy descent project


We are interested in living in a sustainable way that looks after the environment we like to spend time in. We are also interested in ways of doing things that promote the local economy and culture. Renewable energy is an opportunity for both powering our lives with clean energy and working towards these broader goals.

The idea of the EcoBro Energy project was to look at the problem of energy in a way that is thorough and relevant to our lives by looking at real houses around Snowdonia, North Wales, rather than national statistics. To see our energy picture now, and what challenges, solutions and opportunities are available.

We looked at household energy use for electricity, heat and transport and how much of this energy comes from renewable sources. We also looked at levels of insulation and other energy saving measures in the houses. 17 houses took part in the study.

The graphics below show a picture of where we are now and what the effect of changing our heating systems and electrifying transport would have. It shows the potential of the measures and how they can add up.

The following presents our initial findings:

Update: View an interactive version of the findings (


Solutions for getting to 100% Sustainable Energy

In both the ZeroCarbonBritain report and David MacKay’s Sustainable Energy without the hot air, building retrofit (insulation and air-tightness), heatpumps and electric vehicles form the cornerstone of both significantly reducing the amount of energy we need to provide the same amount of comfort/utility and making it possible to power the remaining energy demand from electricity generated by renewable energy.

The following graphics show’s what the effect would be if each household in the study applied these measures.

1) 100% Green electricity tariff

Perhaps one of the easiest measures is to switch to a 100% green electricity supplier. We can also go further and take a hand in actually generating renewable electricity ourselves, whether from roof top solar PV or from a community wind, solar or hydro installation.


2) Heating provided by heatpumps powered by renewable electricity or/and biomass heating.

Heatpumps form the cornerstone of supplying the remaining heat demand after retrofit in both Zero Carbon Britain and David MacKay’s sustainable energy without the hot air. Heatpumps when installed correctly can provide 3 units of heat into the home for every unit of electricity consumed running the compressor. A heatpump works in the same way as a fridge or air conditioning unit, instead of cooling the inside of your house it takes heat out of the outside air and radiates heat into the house.

The graphic below shows the effect of replacing every oil and gas heating system with a heatpump running at an average coefficient of performance of 3.0.


3) Switch all petrol and diesel cars to electric cars powered by renewable electricity

The simple model applied here assumes that the number of miles driven stay’s constant. The ZeroCarbonBritain report from CAT suggests a reduction in the number of miles driven through a combination of increased use of public transport, walking, biking and better planning of where we live in relation to work/activities in addition to a switch to electric vehicles which are both more efficient than petrol and diesel cars and can be powered by renewable electricity.


4) Electric trains and buses instead of plane’s

In order to achieve the last 15% and still enjoy travelling long distances we would need a switch from flights to electric train journey’s, the model here just assumes that the number of flight miles are replaced with electric train miles powered by renewable electricity. Electric trains can be a very efficient way of travelling long distances, see section on better transport by David MacKay


5) Retrofit buildings to achieve at least 120kWh/m2 primary energy requirements

Improving the thermal performance of buildings by adding insulation and improving the air-tightness should be one of the first measures applied and considered before or at the same time as any heating system changes. The EcoBro Energy study did not look in detail at the potential for retrofit in the houses studied.



This project was funded by the Snowdonia National Park’s CAE (sustainable development) fund & Cyngor Gwynedd’s CIST fund and kindly sponsored by:

Screenshot 2017-03-27 at 16.48.18