Contractor Blog

The best direction for a roof with solar panels is dead south. Except if you're in the Southern Hemisphere when you want it to be facing north - which is why solar panels are like bath water spiralling down the plug hole.

But few people in Guildford have a roof that faces exactly south. And few people in Guinea have a roof that faces exactly north. So the key question for many of us is: "How much solar generation do I lose if my panels don’t face exactly south?"

Research indicates the market for curtain walling is growing at a healthy rate of around 6% per annum. (A curtain wall is the non-structural weather proof covering of a building, generally associated with large multi-storey buildings.) This rise is driven both by new build construction and by energy efficient refurbishments of existing buildings.

Standard curtain walling improves the thermal insulation of the building, leading to reduced HVAC costs and reduced heat loss. It also improves the aesthetic appearance of the building.

A photovoltaic curtain wall has the added benefit of generating electricity over the building’s life.

Whilst it costs a bit more than standard curtain walling, the incremental cost of a BIPV facade will typically be paid back within around five years.

If you have a requirement for Solar PV as part of any project in Q1 or Q2 this year, we recommend you place an order for the installation as soon as you can in order to secure stock, current low prices, and installation labour.

The overall trend in the solar PV industry is one of technological improvements (more Watts per 60 cell panel), and manufacturing improvements (lower prices), but in the first half of this year a perfect storm is brewing leading to limitations in supply, and the potential for increasing prices.

Three factors are at play:

If you are building a new property or re-doing a roof and want to install solar PV, it makes sense to look at roof integrated solar panels.

There are a few systems on the market, for example Viridian Solar and GSE.  But one system in particular, Easy Roof Evolution, stands out if you want Velux® windows within the solar array.

Two or three weeks ago we launched a 'Back-of-Envelope' Solar PV Calculator.

You can access it here:

I have been using the calculator to get a rough idea of what the returns from solar PV look like in a post-subsidy world, without bothering our Estimating team (who, as you can imagine, are pretty busy in the run up to the Feed-in Tariff closure on 31st March 2019).

Here's an example of what 75kWp of un-subsidised solar PV looks like, retro-fitted to a factory roof...

If you are involved in electrical specifying, it’s only a matter of time before you are going to have to specify electric car chargers as standard on many of your commercial sites.

Whether you are installing a single commercial chargepoint, or a multi-site network, there are a few things you need to consider when choosing a charger brand and model.

We’ve written a 2 minute guide below: