WTF of Energy Efficiency: A Quest for the Right Metrics

What is the most common issue we solve at Energomonitor, where we develop Internet of Things solution for energy savings?

Well, except for the fact that Czechs don’t consider energy savings worth it, which contrasts with the approach of Dutch or Spanish customers?

Our biggest issue is to communicate to the customers ways of getting the most out of Energomonitor.

When someone from our team looks at readings on a energy consumption graph and after taking into account “the kind of heating and kind of property”, they can find out where there is room for improvement. Most customers aren’t able to do this and we cannot interpret the graphs for everybody. So the struggle is with how to communicate to the customers, ways of getting better performance.

Let’s look at ways to make energy savings. We have created a list in which we follow these parameters:

  • the amount of potential savings
  • investment
  • interference with the user’s convenience, habit and repetition
  • the possibility of automation

There are several different approaches in this list. Take, for example insulation of non-insulated house. It is capital-intensive, it is significant intervention into the user’s convenience, it’s a one-off and there is a high amount of savings in heating. The insulation is always worth the money, but not everyone wants to do. Here are some simple tips and tricks how to change things get savings and do it with very little work.

The numbers we used here are made up. We did this so anybody, even with very little knowledge of energy, can understand what we are doing.

Minimal electricity consuption

Let’s look at the example of minimal consumption. We have defined minimal consumption as the lowest continuous power consumption, which is in the measured property reaches.

It would seem that the lowest electricity consumption is zero watts, but that’s not true. In households and small businesses there are number of appliances that are in stand-by mode, or permanently draw some current. Doing so throughout the day to a considerable amount of energy used. If the customer does not heat with electricity minimal consumption can easily be over half the cost of electricity.
Firstly, you won’t be able to measure your minimal consumption without Energomonitor or some other smart metering device. Your tool has to be able to measure this minimum consumption and any consumption from repeating process.

What can we do about?

You can check the individual appliances and determine whether it is necessary to have them on or even in stand-by mode. Usually this is the case with old appliances like grandpa’s old radio that is still plugged in but nobody uses it. The transformers of bigger appliances usually consume something, even if the device appears to be disabled. Appliances produced up to 2003 are very problematic is this regard and devices produced up to 2006 also have many issues with stand-by consumption.

Then came the cursed EU regulations that penalized the sale of appliances that consumed in stand-by mode.

When you bought an appliance the last time, did you check if it consumed energy in stand-by mode?

After optimizing the minimal consumption, you should get below 30 % of total consumption. How does such a difference translate into the budget? The figure below shows a typical family house, where the electricity is not used to heat the house, but it is used only for heating water.

(30 Kč is 1 Euro)

Before optimization the minimal consumption was about 40% of the bill and after optimization it has fallen below 25%. The difference in the cost of electricity including the dividing rate and using the actual consumption is about € 200 per year, household savings by not connecting appliances that are not used.

However, this does not mean that the DVD player or television are not plugged in. These appliances should be in Saving mode and only take 5 seconds longer to start. But the rarely used desktop computer should be unplugged.

Problem of permanent consumption is that there is not a one time solution.

It is necessary to check the consumption, regularly. The next graph shows that minimal consumption over a year at the house is slightly increasing.

Red regressive line says that growth is statistically permanent and is increasing with connection of new appliances. You should ask yourself if this 25 W increase about 30EUR year, is returned at least in personal comfort. Or if you are just throwing money out the window? Are you returning to your original habits (desktop used once and plugged back in the socket), or if you have new appliances that are causing the higher cost. That is something you have to decide yourself.

The energomonitor tasks are in this case as follows:

  • prepare an understandable metrics and explain it to you
  • offer you a comparison for the measured values
  • advise you on how to achieve better results
  • motivate you to have a better result
  • a long term monitoring whether the result has not worsened and possibly help to improve it or make an assessment that financial deterioration led to improving your personal comfort, or has other benefits.

It was my intention to show at least partially, in what direction and manner of data analysis we can do. In fact, the subject is much broader…