Energy Saving at Pico Technology

Here is our electrical energy usage since we moved into the building.  The data is taken from weekly meter readings.

As you can see, the readings were very high when we moved in, because of the high energy consumption by the previous occupants, but our usage soon levelled off as we adjusted the heating and lighting.

This is James House, our new building on Colmworth Business Park, Eaton Socon.  It's luxurious compared to our old, cramped premises!

The building is still set up for the previous occupants, an electronics assembly company.  They have installed high-density lighting for the soldering stations, and the heating is set to 24 hours a day, 7 days a week because of their non-stop production schedule.  As a result, our first electricity bill is equivalent to about £55,000 a year, which is a huge increase on the cost for our previous building.

Our first task is to change everything to suit our production methods and working hours.

Like most office buildings, James House has some large banks of unlabelled light switches. Nobody knows exactly which switches correspond to which lights, so they usually just switch them all on in the morning. We have solved this problem by sticking green stickers on the lights that we normally want to be on. This should save about 25% of our lighting energy consumption.

A few months ago we wrote about the water heater, and gave some figures for its energy consumption.  That was with the heater in use, with water being drawn off regularly.  Now that the heater has been replaced by a new wall-mounted one, we have just done an experiment with the old one to see how much energy it uses when no water was drawn off.

We filled the heater with cold water, switched on the power and left it alone for about six hours.  The energy consumed in this time was 2.34 kWh.  This amounted to an average power input of 376 W, compared to the figure of 488 W that we obtained when the heater was in use.  So the difference in the figures, 112 W, is the amount of power needed to heat our drinks.  That means that about 80% of the energy is being used to heat the room, and only 20% is going into our drinks.

We can't measure the energy input to the new heater (Instanta WM7 SS) because the cabling is buried in the wall, but the manufacturer claims that it uses 120 W when idling.  This would be a big improvement over the 376 W used by the old heater (although that figure was slightly pessimistic as it included the energy taken to heat up from cold).

We've been replacing a number of old CRT monitors with new TFTs, so we thought we would take some power measurements of the old units before we threw them out.  Here are the results (all numbers in watts).