20 free hot baths one March weekend

Close to 100% of generated electricity used onsite (graphs).

A selection of graphs from the EMMA and solar PV system at Deer and Dexter farm. This data was recorded on several dates in March 2012.


The data below was taken from Deer-n-Dexter farm, on 22 May 2012.
The EMMA being used is an EMMA SP15/60 3G GVS. The solar PV system is 20kW.

Graph 1 – 3rd March – from 8am to 1pm

Click for a larger version of Graph 1.


Graph 2 – 3rd March – from 9am to midday

Click for a larger version of Graph 2.

Graph 3 – 3rd March, from 1pm to 2pm

Click for a larger version of Graph 3.

Graph 4 – 3rd March – from 1pm to 4pm

Click for a larger version of Graph 4.

Graph 5 – Saturday 10th March – from 8am to 2pm

Graph 5 shows the PV system putting out a significant amount of power over a weekend in early March 2012.

EMMA successfully enabled almost 100% of the generated power to be diverted to the onsite thermal store.

Click for a larger version of Graph 5.

Graph 6 – Saturday 10th March – from 10.30am to 11.30am

EMMA precisely matching site demand to what is being produced by the generator.

Click for a larger version of Graph 6.

Graph 7 – Saturday 10th March – 12.40pm to 1.15pm

Click for a larger version of Graph 7.

Graph 8 – Saturday 10th March – Hot Water Temperature

Graph 8, below, shows the thermal store being heated by the surplus/free power on the Saturday.

The water temperature rose 10 degrees on  the Saturday, and another 10 degrees on the Sunday. It is a huge tank, at 2,800 litres. A 10 degree rise is equivalent to circa 33 kWh, which is equivalent to 10 hot (45 degree) baths a day – for free – or 20 in total over the weekend!

Click for a larger version of Graph 8.


Almost 100% of generated electricity used on site

The EMMA meters were read on the Sunday 11th March. The readings were as follows:

  • Power consumed: 899.00 kWh
  • Power generated: 307.31 kWh
  • Power imported: 595.93 kWh
  • Power exported: 4.24 kWh

These figures were totalled since the previous time that EMMA was reset at the site. They show that EMMA just about eliminated all export (or waste) of electricity for the farm.

This enabled the owners of the PV system to avail of close to 100% of their PV output, which represented about a third of their total electricity requirement during this period.

More from Deer n Dexter

Also see earlier posts related to this installation of EMMA:

ELITE Control

The ELITE is the latest addition to the EMMA product family. While we consider it to be the Elite of power diversion and monitoring it is in fact EMMA's little sibling or as we call it EMMA lite.


EMMA Cascade

The modular heating system that can grow and grow


EMMA with Export Control

EMMA with EC allows for installs to have a greater renewable output than the Max Export Capacity (MEC) on site by diverting excess energy to heat.