Problem Addressed

How to enable every apartment in the UK to source energy from renewable sources as part of the UK’s pathway towards net zero carbon. A great solution to this is rooftop solar, however, a practical solution for apartments has historically been hard to come by.

Solution Overview

Allume’s SolShare is the world’s only hardware for connection multiple flats to a single rooftop PV, solving the longstanding problem of how to gain the numerous benefits of solar PV for flats.

SAP 10.2 states that solar PV must be directly connected to each flat in order for it to benefit from the solar PV SAP score uplift. SolShare qualifies as a direct connection and typically adds 5-15 SAP points to every flat.

More importantly, you are able to allocate the specific kWp that each flat receives. This means that you can allocate more kWp to flats that need to achieve a higher SAP boost to achieve a specific EPC rating. An example of this is detailed in the case study section.

A fully installed SolShare system typically costs £1,500-£3,500 per apartment. The range of this is mostly down to the system size connected, and therefore the SAP point uplift. As an indication, an investment of £2,500 is likely to achieve 10 SAP points.

In addition, SolShare solar PV also helps to reduce energy bills for residents and therefore helps alleviate fuel poverty for low-income households.

Due to the significant benefits at a relatively lower cost to other solutions; SolShare is applicable for numerous funding initiatives including SHDF and ECO4, where Ofgem have classified SolShare as an innovation measure of substantial uplift – resulting in a 45% uplift in available funding.

Allume offer free consultation on any apartment building that may be suitable for a SolShare system. This includes:

  • System design and suitability
  • Indicative SAP score uplift
  • Indicative pricing

Once the project is underway, Allume also offer free wiring and system design advice.

Case Study

SolShare has been used on apartment buildings that range in size from 4 to 550 flats. Here are some case studies.

TopHat – 90 flats – requirement to hit EPC B

Modular house builders TopHat has used SolShare to increase all 90 flats in a building from EPC Cs to EPC As. Each flat required a different allocation of kWp to benefit from a different SAP point uplift to achieve this target. Below gives the details of this uplift for 15 flats in the building:

  • Flat number: Initial SAP score & EPC + kWp allocation = resulting SAP score & EPC
  • Flats 1-4, & 9-12: 72 C + 1.5 kWp = 81 B
  • Flats 5-8, 13, & 15: 76 C + 1.0 kWp = 82 B
  • Flat 14: 80 C + 0.5 kWp = 82 B

Silent Project – SAP miscalculation

Allume was contacted by an M&E contractor who had discovered 4 weeks prior to completion that the air permeability of the flats was not as high as planned. This resulted in numerous flats in the building not hitting their EPC target of A.

SolShare was the simplest and most affordable method of bringing those flats back up to an A.

The system was designed, installed, and commissioned in less than 2 weeks.

Facts and Figures

5-15
£1,500-3,500
40 %

This page presents data, evidence, and solutions that are provided by our partners and members and should therefore not be attributed to UKGBC. While we showcase these solutions for inspiration, to build consensus, and create momentum for climate action, UKGBC does not offer commercial endorsement of individual solutions. If you would like to quote something from this page, or more information, please contact our Communications team at media@ukgbc.org.

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