STA Scotland asked the DNO to analyse several case study connections showing the modest network impact of most rooftop solar projects in practice. After further calculations and consideration, the DNO thereafter agreed to relax restrictions, from 1st April 2018, on small and medium sized solar installations (up to 200 kW), which will now find it easier and cheaper to connect to the grid in Scotland.
Data provided by STA Scotland members across a range of solar installations led SPEN to conclude that the effect of most on the local grid was much less than previously thought. SPEN had required a 'Statement of Works' from developers seeking to install even small solar projects over 11 kW. This meant developers had to commission a costly and time-consuming analysis of how projects may affect transmission loads at national level, adding over £10,000 to some project costs. Also, where fault levels are high on the network, SPEN also confirmed they would only consider these in connections over 200 kW, although voltage rise calculations will still apply.
“This is a breakthrough for solar in Scotland and it goes a long way towards removing one of several barriers to Scotland realising its solar potential” said STA Scotland Chair Chris Clark. “We're grateful to Scottish Power Energy Networks for engaging with our members and for looking carefully at the evidence. As a result of SPEN taking a sensible approach to rooftop schemes, businesses and housing developers all over Scotland will find it easier & cheaper to go solar”.
Developers, consultants and architects can now look again at solar as a solution to making their buildings more efficient.
The decision will have a significant, material impact on the economics and attractiveness of going solar, particularly for the commercial rooftop and multi-scheme new build housing sectors. The STA has been holding meetings with Distribution Network Operators in Scotland on the impact of outages and curtailment on solar PV projects.
Clark added that the STA is looking forward to deepening its collaboration with SPEN as the networks transition to smart, active Distribution System Operators able to make full use of the many services and potential cost savings solar PV and energy storage can deliver.
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