With technological advances come opportunities to integrate renewable energy systems into developments, increasing the sustainability of homes, reducing the pressure on fossil-fuel provisions and cutting running costs. Renewable technologies are available now and, although slightly more costly in outlay, offer savings over time as technology advances and lifetime energy usage is reduced. Some homes currently being developed are even energy-positive, meaning they produce more energy than they use. This surplus can subsequently be returned to the local or wider energy grid.

Renewable energy technologies include:

• Solar power systems – using the sun’s energy to heat water or generate electricity.
• Wind electric systems – using turbines to generate electricity.
• Hydropower systems – using a nearby moving water source to generate electricity via a turbine.
• Biomass – burning plant products or animal waste as fuel to create a heat source.
• Ground-source heat-pumps – use underground pipes to extract heat from the sun as a heat source.

These renewable technologies can be used at varying scales alone, in connection with each other or in combination with fossil fuels. It is important to remember that certain renewables are not appropriate for some sites: for example, hydropower is only viable in developments close to a moving water source, whereas biomass systems can be implemented anywhere. Therefore when considering renewable infrastructure the appropriateness of specific systems must be considered in the context of the site.

Another consideration is whether the system is connected to the grid or a standalone system. Standalone systems are suited to small, remote developments where connecting to the grid is less cost-effective than the renewable system itself. Connecting a renewable system to the grid means electricity can still be used if the renewable energy supply fails or energy requirements are not met. Connection to the grid also allows the selling-back of any surplus energy (via the Feed-in Tariff, introduced in 2010).

A good example of the incorporation of a renewable energy system in a new development comes from a housing scheme in Neath, Wales. The development of 16 homes uses solar collectors on the walls of the properties to create a source of electricity, which is stored in a shared battery on the development until needed. The unique roof design makes use of a perforated steel skin to create pockets of heat under the surface when the sun shines; this heat is then drawn into the homes and used for heating. If successful, this pilot scheme could serve as the start of a nationwide initiative mitigating the need to build new power-stations.

New developments should consider the incorporation of renewable energy systems at the design stage. Plans should seek to accommodate the related infrastructure not only inside and on individual buildings, but within the wider community layout. This may necessitate measures including:

• The provision of appropriate ducting and utility services.
• Designing adaptability into homes – for example, allowing for the conversion of roof tiles to solar tiles.
• The provision of internal storage space for batteries (in their current and possible future iterations).
• The accommodation of central energy stores and their potential for future maintenance and upgrading as technologies advance.

The Architectural Details section contains further information on how buildings should be orientated and laid out internally to maximise the efficiency that can be achieved from natural light and heating.