ECO HHCRO cost saving calcs for solar PV with storage heaters????

Gavin A · Oct 9, 2015

Looking at ways to survive post 2015, and remembered a possible project we'd looked at a while back for a housing association in flats with all electric storage heating, which means that solar pv qualifies for ECO funding under the HHCRO stream.

But I can't find any guidance on how to calculate the lifetime cost savings for this combination - lots of guidance for gas boilers that seems to massively inflate the savings possible, but sod all for PV and storage heaters + immersion heating hot water.

Has anyone done this / does anyone know how to do these calcs?

I've no idea if it's viable or not, but would like to run the figures to find out if possible, so any advice appreciated.

Thanks

TedM · Oct 9, 2015

The general cost score methodology for HHCRO for non-boiler and non-insulation measures is simply the annual saving (from RdSAP before minus after PV calcs) times the 25 year lifetime defined for the measure.

Formula 1.1 in Section 7b - p67 in this doc: https://www.ofgem.gov.uk/sites/default/files/docs/2015/03/delivery_guidance_0.pdf

But this is to be calculated by the electricity supplier claiming the ECO2 measures not the installer.

Or are you talking about something else?

Gavin A · Oct 10, 2015

I think that's the calc, we need to do the calc first as the way the bidding for the funding seems to work is for the company with the funding to specify a target rate that they expect all funded projects to be capable of hitting.

I think that's what I was talking about, but was hoping for a specific example of how it'd work for PV as it's not terribly clear..... is 25 years the lifetime for solar PV in those measures then?

I'm just not sure if you can claim for the entire solar generation, or just some proportion that is nominally towards the heating, also it seems to be using SAP for the calcs, is this still correct?

I've see 2 offers at 7p and 7.5p per kWh, which would have been terrible, but are now actually better than the FIT + Export rates if it applies to all generation, so I'm hoping it might work.

Gavin A · Oct 10, 2015

oh, I think I see, so it's the actual difference between the before and after RDSAP calc on the EPC / green deal assessment?

hmm, I wonder how well that's calculated.

TedM · Oct 10, 2015

Example (made-up figures):

RdSAP on a property with no PV = £800 per year for heating and DHW
RdSAP on same property with PV = £600 per year for heating and DHW

annual saving £200 x 25 year lifetime = £5000 saving

cost of installing PV = £4000

So whether PV stacks up as viable for HHCRO will be determined by the supplier dependent on if the £4000 cost to save £5000 is better/worse than any of the other options they have for meeting their HHCRO target.

Also note that HHCRO is only available to householders/tenants who are in receipt of certain benefits (Affordable Warmth Group - AWG), which has to be evidenced. So not necessarily available to all who are in social housing.