Wind energy analysis

At a UK national level, there is a better interseasonal match between wind resource and electricity demand than with PV and a well placed onshore wind turbine at scale will give a lower lifecycle cost per unit of electricity supplied than PV.

However, wind energy projects are significantly more complex than PV projects and are only suited to very specific locations with uninterrupted wind resource and where the impacts of the turbines are within acceptable limits. PV arrays on the other hand can be installed in a wider range of locations, and can be designed to make a valuable contribution to supplying electricity demand.

It may be that as PV continues to develop and come down in cost, it will become economical for it to be oversized to give more of a contribution to winter electricity demand, with any excess in the summer used to produce transport fuel or stored in another form.

Priority should always be given to reducing energy demand before determining the appropriate form and scale of renewable energy supply, in accordance with the Energy Hierarchy. However, there may come a point whereby there are diminishing returns from the implementation of demand reduction measures and renewable energy is a more economically attractive proposition.

For example, once a certain level of insulation is reached for a retrofitted building, then it may be uneconomic to carry on increasing the level of insulation and reducing the size of a biomass boiler or heat pump to supply the heat. However, it is not only the current costs that should be taken into account when deciding on the balance - the greater the level of energy demand reduction that can be implemented, the less the exposure will be to the future volatility of the energy supply market, renewable or otherwise.

Renewable energy is already cheaper than fossil fuel energy in many cases. For example in the UK, onshore wind energy and large scale solar power give lower cost electricity than fossil fuel generation.

There are hidden costs and benefits associated with the use of fossil fuels that are not always taking into account when comparing with renewable energy.

Benefits include upstream subsidies and hidden costs include those of mitigating or repairing the damage caused by fossil fuels (external costs). When these external costs are taken into account, renewable energy can be even more attractive.

It is expected that with time and the pressures of climate impact, these external costs will be internalised and a view might be taken on this when investing in renewables.