Solar Panels for Offices

Offices would greatly benefit from having solar PV panels — in fact, most office buildings in Ireland require a deep retrofit to drastically upgrade their energy efficiency rating.

60% of office buildings in Ireland have a Building Energy Rating (BER) of D or lower, while only 2% of offices have an A rating.

The CSO’s 2024 BER breakdown shows that more than a third of offices are E, F or G rated. For comparison, 47% of schools and colleges are A rated.

Meanwhile new EU energy rules set tough standards for commercial properties to improve energy efficiency and reduce their overall carbon footprint. 

The ambitious European Green Deal requires that offices reach at least a B energy rating – and investing in renewable energy such as solar PV is a great way to move towards this goal. 

And there are some other major benefits too:

Solar panels are especially suited to office units because in many circumstances they have large, flat rooftops which are rare on residential buildings.

This is a major advantage because on flat roofs, solar PV modules can be mounted to face south at an angle of between 30 and 50°, to maximise the amount of sunlight they receive throughout the day.

One drawback to installing solar panels on a flat office rooftop is that the panels take up more space per kW. But as there is usually a larger rooftop area to work with on office units, this is rarely an issue in practice.

While any size of solar system yields significant savings, large rooftops can accommodate larger arrays which can generate significant amounts of electricity.

Ireland had the third highest electricity prices in the second half of 2023 for non-domestic consumers at over 15 cent per kWh and the second highest electricity prices for households after Germany.

High energy costs mean that generating free solar electricity in Ireland can result in huge savings for businesses – but just how many solar panels are needed and how much could you save?

Savings depend on the size of the solar panel system installed (how many panels), as well factors such as roof orientation and angle, location, and the electricity provider’s unit rate.

These are estimates based on the following assumptions: A south-facing roof with solar panels at a 30° inclination and SSE Airtricity 24-hr Smart Rate of 33.31c per kWh

The number of solar panels needed by an office depends on the electricity consumption of the office. CSO data shows the average electricity consumption for offices in Ireland is 27,681 kWh while the median is 11,183 kWh.

Because of the diversity in office sizes and types, the median (11,183 kWh) offers a more robust indicator of overall annual electricity demand for offices.

Those installing PV panels will often aim to have 50 to 75% of their annual energy consumption covered by solar electricity with solar PV systems.

If we take the median office electricity consumption in Ireland, then a 10kWp system would cover 75% of the electricity costs. This equates to around 22 to 24 high quality solar panels, which would take up around 45m2 of roof space.

The cost of a solar panel system for an office unit will mainly depend on the number of solar panels that are being installed.

To install 22 to 24 solar panels, which could cover around 75% of the median annual electricity usage for an office, it would typically cost €14,000 to €15,000, inclusive of optimisers.

However, this is the median, meaning many offices would require a much smaller solar system to cover their costs, while some would need larger installations.

And all our figures are estimates based on typical power output and electricity consumption, the actual price of the PV system could vary depending on other factors.

Property management firm Hibernia decided to take a new approach to installing solar energy at its Central Quay office building in 2022.

A substantial 50 kWp solar PV system was installed on the rooftop through a power purchase agreement with the ESB which financed the project.

Hibernia’s approach to installing solar resulted in immediate carbon reductions.

Once the fixed period is complete, the solar panels are fully owned by Hibernia and the cost of energy generated is zero. 

Hibernia’s latest environmental report states the firm has solar PV systems with a total peak output of 85 kWp across its Irish office assets.

The Sustainable Energy Authority of Ireland (SEAI) offers grants to support the installation of solar panels on office buildings. These grants can significantly reduce the initial investment required.

The main SEAI solar grant avenue for offices is the Non-Domestic Microgen Scheme, which offers up to €162,600 towards a PV installation for businesses, farms, schools, nonprofits and community buildings, among others.

Several top solar installers in Ireland specialise in solar panel installations for office buildings. 

As with all solar PV installations, it is critically important to choose a reputable installation company with a proven track record, and near flawless customer reviews. 

Our fully vetted network of commercial solar installers are the best in the business, with years of experience in delivering larger solar systems for commercial customers across Ireland.

If you are interested in future-proofing your business with a solar PV system, get a free quote today!