Feasibility Study

Who will get invited to take part?

 

One of the first steps towards installation is a feasibility study. This piece of work will look at the average heat demand of houses as well as the possible routes and the drilling conditions in Stithians. It will allow us to identify properties most suitable for inclusion in the heat network and provide valuable information for planning the installation. This study will include:

Geological survey

This will tell us about the type of material that the boreholes (heat collectors) will be installed in. 

By looking at the geological conditions, we can understand the heat transfer properties of the ground as well as whether there are any issues that could make drilling more difficult. For example, in loose stones a borehole has an energy extraction rate of approximately 20 watt per metre (W/M), whereas granite has an extraction rate of 55 to 70 W/M and the borehole will be strong and stable.

The geological survey should also indicate whether there are any mine workings or aquifers present. In these circumstances we would need to use different engineering techniques such as an open loop borehole that can utilise the high thermal conductivity properties in the subterranean water sources.

Estimate of energy demand

Using freely available property information we will be able to produce estimates of a building’s energy requirements. This gives us an idea of how big our borehole field will need to be to serve the village.

Calculation of borehole requirement

This will allow us to determine how many boreholes are needed to fulfil the requirements of the heat network. It’s based on the thermal conductivity of the ground and the heat demand of the village.

Options for borehole siting

Boreholes need to be about 5 metres apart. There isn’t much open space in Stithians and we want to minimise the length of the trenches to reach the houses we are heating so we have to plan borehole layout carefully to make the best use of the land available.

Options for heat network routes through the village

Knowing where the boreholes will be located and how many are required the team will be able to plot options and routes through the village.

Best options for value for money

We will also look to deliver value for money for the network, clusters of similar properties will be more cost effective than properties that are more isolated, trenching through roads is more expensive than trenching through open spaces.

Minimisation of disruption

The disruption of residents in the villages will be taken into account to ensure that any impact on people’s day to day life is minimised. This is most important when planning the borehole siting and heat network route as these activities could affect the whole village, not just those benefiting from new heating systems.

How we will use the information.

 

Following completion of the study and consultation with our contractors, we will develop a detailed design of the heat network.

Creation of detailed designs will enable us to rule out those properties that are too remote or too difficult to connect. We will notify all those that have expressed an interest but are unable to take part at this stage.

Properties that appear favourable for connection to the network will be provided with further information regarding connection.