Mr. Cotton

PV System: 12kWp on East / West split
Installation date: October 2015 – upgraded April 2017
Installation time: 1 Day

Wattstor System Components:

  • Wattstor IMP
  • 10kW inverter charger
  • 10kWh of Lithium Ion battery storage

About the Customer

Mr Cotton has been renovating his 1979 bungalow to be eco-friendly and self-sufficient.

He has installed:

  • 12 kW of Solar PV
  • A Biomass Stove (for space and water heating)
  • MVHR System
  • A 500l Hot Water Store
  • A 6kW immersion heater
  • Extra Insulation
  • A Wattstor 10/10 battery system (to help balance electrical load)
  • Hot tub

Mr Cotton’s Export limitation and Energy Management

Mr Cotton wanted to install 12kW’s of PV at his property but was told by his DNO that he would only be allowed to install 6kW’s due to National Grid constraints. He decided to install a Wattstor IMP, which limits export to the grid and diverts generation to supply electrical loads within the property.

The IMP has been previously witness tested by his DNO, and not only allowed the customer to install double the amount of PV, but also enabled him to divert generation into his hot water tank. The IMP also has the potential to divert generation to his hot tub and Aga.

How did Wattstor help?

Wattstor undertook a survey and designed a bespoke system for Mr. Cotton’s property, giving the customer various options to help achieve his aims of high generation and low grid import. Wattstor guided the customer through the necessary steps for obtaining permission from his DNO to install additional Solar P.V generation. We identified loads that the generation could be diverted to, resulting in a highly efficient integrated energy system.


‘’I was looking for an energy management system to control my integrated energy technologies and limit export. I also wanted to run off-grid for as much of the year as possible”.

Neil Cotton
December 2015

Mr. Cotton, St. Agnes