- Cooking – Electric or Gas for Hobs & Ovens
- Heating – Oil fired Heating or Heat pumps.
- Lighting – Tungsten / fluorescent or LED.
To give example of how much costs vary and why, I will take three homes that spring to mind.
Examples of modern homes (2) with heat pump
A year ago I installed a Solar system into 2 Large size family homes approx. 3000 sq.ft. They are a sister & brother and homes are almost identical and situated beside each other on the same driveway. They both got 24 Panels 435W Jinko, 6KW Sofar Inverters and Dyness Batterys.
These homes are modern sealed homes with air filtering systems and Heat Pumps for heating.
One of these homes has two batterys and the owner (Hal) is fighting hard to get to a Zero cost monthly bill. He is very close and has around 85% bills paid annually through Solar..last time I spoke to him (6 months ago)
The second home has one battery and the owner (Andrew) has no bills and actually makes money. The homeowner is an ESB Consultant and benefits from a discounted electricity rate.
I have never asked what the electricity usage on these homes are, but are probably in the 8,000KWh range Annually.
Example of a 90’s home with heat pump
Now,
Today I started work on a Home, Dormer bungalow around 2,400sq ft with a granny flat (home out the back) around 1000sq ft at the most. Total 3,400 sq ft.
I am fitting a Sigenergy 5KW Inverter, Gateway, 9.0KW Battery and 27x 460W Jinko solar panels to help alleviate the pain with his bills. 11.88KWp and estimated 8,736KWh Annually.
The bills are costing them a staggering €1300 every two months!! €650 per month!
This is what the client told me today and we are only getting into winter.
He has an Air to Water system (Heat pump) to heat the home and is blaming his bills on this.
Now I don’t know much about heating, but I believe that heat pumps require a sealed home to operate efficiently. They use a lot of energy to quickly build the heat up and once temperature is reached, maintain that temperature with little effort because the home is sealed. Hence why it is important to have an air purification system/filter in place.
The issue I see in this home is that it is an open attic with no sealing, as most homes pre 2010 are. They are not designed for heat pumps from what I understand. The heat pump is kicking in hard to build up the temperature, but the heat is escaping everywhere! And the heat pump is kicking in hard to build up the temperature!!
End Result
But the point of this excercise is that you need to understand there is a limit of how much energy that can be created under the ESB Networks limitation scheme on the NC6 – 5.5KW Max Inverter with 5.5KWh export and somewher around 24-27 panels dependant on direction.
Unfortunately the Solar system installed at its maximum size will only pay part of his bills – around 4 months, around 33% from a full size system.
Resolve the Mismatch
He absolutely needs to go, look at his heating system and find a way to resolve. It looks like he was sold a system on bad advice that is not suited to his home, but likely grant supported and now has enormous bills…until resolved.
