For consultants, energy reports for planning are fantastic: a bit of SAP, a few benchmarks, some spreadsheet magic, and hey presto you’re sending an invoice. But the contents of the energy report can have huge implications, in some cases committing the scheme to commercially or legally impossible strategies, causing delays and increasing costs later in the programme. Here are a couple of examples:
Looking at how to hit 20% on a recent development for an RSL in London, we arrived at a predictable crossroads: PV vs. wood pellet heating. The planners had already required a communal heating system so it looked like a no brainer for the client: £500k for a PV array vs. a £70k boiler.
But looking closer, it wasn’t that simple. Heating from wood pellets costs more than heating from gas, raising some tricky questions for the RSL:
- Could the RSL reconcile more expensive heat with its own mission and fuel poverty targets?
- Heat networks are unregulated. What consumer protection measures will be required? Does the RSL already have a customer charter for heat?
- What would the tariff setting mechanism be in order to ensure prices are transparent and the occupants get a fair deal?
- How to you incentivise the operator to use biomass rather than simply letting the boiler sit idle?
- If this boiler sits idle, what are the reputational, regulatory, and commercial risks to the RSL?
- Etc!
On another job, the sustainability consultant (not us) had recommended PV as part of the strategy to meet planning requirements. But in order to get the required area on the flat roof, they’d crammed the rows in very tightly.
Looking at the job post planning, the only way we could see to avoid self-shading was to significantly decrease the panel inclination. This reduced output and meant the scheme wouldn’t hit its 10% target.
The design concept also had the electricity going back to individual flats over private wires in order to share the benefit of on-site generation. This raised new questions:
- How will the balance of electricity be supplied? Who takes debt risk? How will tariffs be set?
- Is there a plan in place for providing third party access?
- Is private wire necessary from a SAP and CSH point of view? If not, do the costs of this arrangement outweigh the financial benefit to the occupants of generating their own electricity?
These are just a couple of examples. But they illustrate that for clients a planning report is a very important strategic step rather than just a box ticking exercise. And consultants have to watch out too – while planning reports look like a simple piece of consulting, they might leave you with some difficult questions to answer down the line.
Yep, couldn’t agree more with every word. A quick note on the last question: There are no specific requirements in CSH for private wire. Also, within SAP, it is acceptable for a block of flats to have a pv array with single grid connection. The output of the PV must be shared proportionally to each dwelling pro rata based on floor area.
This leads to some tricky spreadsheet magic when aligning say a 10/20% strategy with CSH 25% / 44% DER reduction. As you need to make sure that the quantum of PV to hit 10 or 20%, ensure each dwelling hits the CSH 25% or 44% der reduction when split according to floor area. INvariably this means increasing the array size over the 10/20% scale somewhat.