Adding Solar Panels to your roof

The use of solar panels on the roof space is getting more attention lately as the costs have come down the last few years.

Under the Building Regulations – Part L there is minimum level of energy provision from renewable energy technologies. There is three ways to meet these minimum guidelines:

  1. 10 kWh/m2 /annum contributing to energy use for domestic hot water heating, space heating or cooling;
  2. or – 4 kWh/m2 /annum of electrical energy;
  3. or – a combination of these which would have equivalent effect

In this analysis I am looking at Option 2 to meet the buildings regs for a new build. The manner on which i propose to do this is by means of PV panels. (PV-solar photovoltaic)

Taking the standard size of a Semi-detached house, two-storey with a total floor area 110m2 the minimum electrical energy that must be produced a year is 440 kWh.

To achieve this output it will require two of the 260W peak PV panels. The total area required on the roof for this is 3.27m2. The additional weight on the roof due to the panels is 37kg.

Taking the Irish national average electricity consumption of 5,300 kWh per annum part L has meet 8.3% of its needs. The typical cost of this energy usage generated by the PV would be 75 euro per annum. The avoided CO2 would be 210kg of carbon a year.

Of course you don’t need to be building a new build to add PV panels to your roof. You can do this on an existing property. The cost of two additional panels is less than €600 using a quoted price of supply, install and commission price of 1.20 euro a watt. In bulk this can be reduced to less than €500, not much of an impact on the bottom line. If you want 4 panels you are looking at a cost of somewhere between 1500-2000 by the time the additional works are done. This would be a valuable addition to any roof though.

Heaters

What Electric Heaters to choose?

Robust often get asked the question what electric heaters are best to use?

“I hear that this new type of heater is more efficient and the best to get”

The answer is never yes or no or as simple as choose this model.

In essence the best heating is no heating! What do you mean no heating? Well the best thing is to have you house well insulated and draft proof so your need for heating is minimized. Following this the best heating is really going to be the cheapest.

If mains gas is available this will almost always be the best and cheapest option.

In regards apartments where electricity is the means of heating your options are reduced. Whats important to remember is don’t let a salesman tell you that their electric heating is the most efficient.

how to choose an electric heater
€25 2kW Electric heater vs €550 2kW Electric Heater

Electricity is 100% efficient in that the electricity that comes in at the meter is discharged as heat. So 1kW of heat from a fan is the same as 1kW of heat from a storage, the same applies to the new ‘efficient’ electric heaters and existing convection heaters. The cost of this heat is also exactly the same. The modern designed electric heating comes with a digital programmable interface and thermostat to make them a ‘smart’ radiator.

The picture above shows two 2kW electric heaters. The plug in convective heater is only €25 and light and portable. It has no intelligence or safety features. The wall mounted smart heater is over 20 times the price for the same power output. Yet its a smart programmable safer heater with a less stiffing type of heat output. It’s important to note that if the property is intended for rental purposes the heater must be  “a permanently fixed appliance or appliances capable of providing effective heating.” This rules out the use of a portable plug in heater in a rental property due to regulations.

Choosing storage heaters over electric heaters in an apartment requires some consideration. Do you have a night rate meter as you can use these to get half price electricity at night time. Note the day rate is higher than standard though hence the consideration to your unit rate.

how to Keep your apartment warm
Keep your apartment warm

Storage heaters can be very useful when run on this cheaper electricity. The new style of electric heaters are intelligent, you can program them to come on at intervals. This gives more control but not more efficiency or cheaper. You can make them work out cheaper by utilizing less energy though but you will also have heated your space less. If the rooms are old and liable to damp care is need on your choices.

Installation Costs of heaters:

The cost of installing of electric heaters can vary quite a bit. You can go with zero installation costs with plug with heaters, convection or oil heaters. This can be easily moved around also.

The key difference between storage heaters installation and the programmable electric heaters is weight. A 2 kW storage heater will weigh 125kg whilst the programmable electric is just 22kg. The installation time is usually quicker and easier for the non storage heaters. Some trademens really don’t like dealing with the heavy installation of storage heaters once they have used the easier installation of smart wall mounted electric heaters. Don’t always trust the trademens that recommends this is the best option. Have a look around and ask an expert.

Contact us for further advice or if you want to upgrade your old heating systems.