An Energy Statement is a planning document that is used to demonstrate a projects sustainable energy credentials at the point of making a planning application. Sometimes this report is called a energy strategy, or the information included within an energy statement can form part of a Sustainability Statement.
Of course the above are just names adopted by planning authorities in different parts of the UK, and the content relating to energy is broadly the same. That is the energy hierarchy is addressed and then renewables are selected. The report will sometimes include a building energy model such as SBEM or SAP Calculations.
The Energy Hierarchy is explained within the Energy Statement. This works on the principal of conservation of energy and the efficient use of energy, the use of clean energy (e.g. low NOx) and finally the use of renewable energy.
In the "London Plan" this approach is described as LEAN , CLEAN and GREEN. Which is neat.
Features highlighted in the energy statement would include insulation and air tightness (no draughts), as is encouraged with the new Fabric Energy Efficiency Standard. In short there no point adding lots of renewable to the building if all of the energy will be wasted because the building is poorly insulated etc.
The modern condensing boiler is a a very efficient beast, yet when compared to a regular non-condensing boiler it produces high concentration of nitrous oxide. When installing 60 boilers for a block of flats this has the potential to lower air quality in the area. Of course of low density housing condensing boiler a quite acceptable and this stance would be reflected in the energy statement.
Renewables can be added to lower the carbon intensity of the building energy foot print (lots of jargon there!), they are also fast become an attractive "middle class" features for prospective home buyers. Also unlike the first two step in the hierarchy, they are visible on the roof or facade of building, which adds to the kudos.
A renewable options appraisal will look at the various types of renewable energy available and how they might suite the building. Solar panels of some sort . . probably. Wind turbines on the roof, almost certainly not.
These can be very simple for smaller sites, or very complex for larger sites where potential locations for centralised renewable energy infrastructure have to be chosen with care.
Lastly a point aside. A great many people (house builders etc.) bemoan the cost of renewables saying that the pay back period is too long . . . . renewables such as solar voltaic panels are fairly unique in that they do actually have a pay back period! Does your boiler have a pay back period? No it just costs you money.
All the above be rather meaning less without some number to base things on. After how can you accurately say how many solar panels you need to provide a 5% reduction in (Dwelling Emission Rate) DER, if you do not know the DER?
SWEL use proprietary software to create a whole building energy model. For larger developments we may model each units types and create a development total based on these modeled units, either way it will provide us with some numbers with which to work.
Use this software model we can recommend systems that will not only meet building regulations but also earn extra income for the land owner in the form of renewables subsidies and energy sales. In London for example combined heat and power ticks so many boxes for efficiency, and extra income it is hard to ignore as an option.