How much power and energy does ClearVue glass generate?

Each 1m2 of ClearVue windows is currently rated to generate about 30 Wp of electric power, tested and confirmed by one of the world’s leading technical service organisations TÜV SÜD in China, using windows of size 1.44 m2. The energy produced by windows depends on the installation location, system orientation, tilt angles, system design and implementation, seasons and weather, etc.

Per day

The approximate formula for a skylight or a tilted roof-mounted window facing towards equator is simple: Daily Power = 30 Wp/m2 * (Number of m2) * (Number of peak sunshine hours for the location). In Perth, 10 North-facing roof-mounted windows of total area 10 m2 will produce approximately 30W/m2*10m2*4.5h = 1350 Wh = 1.35 kWh of electric energy daily.

A very close result is obtained by using open source solar data and online calculator published by the National Renewable Energy Laboratory (NREL, USA) at which produces 1.38kWh accounting for a 14% system loss.

At Warwick Grove test installation, the daily averaged energy production is near 1.6 kWh, generated by approx. 25 m2 of windows installed in 4 different sections of the structure. Due to the effect of non-optimum angles, and some strong shading, the averaged energy production figure is close to 70 Wh/m2/day.

It should also be noted that these energy production figures have been measured after the battery storage losses (around 10%), and the DC-to-AC conversion losses (min. 10-15%), thus showing only the approx. 75-80% of the actual energy generated by the solar windows. In future, larger-scale installations of solar windows will run at reduced rates of electric power loss, be placed in different optimum orientations not placed in a shaded environment.

Per year

In Perth, Western Australia with approx. 300 sunny days and 65 cloudy/rainy days per annum, we evaluated that approx. 605 kWh will get generated annually by the 18 active PV windows installed at Warwick Grove. The measured data accumulated over the period between May 2019 – May 2020 shows that we generated approx. 500 kWh/year, as measured from the storage system, and past all electric losses. Given that the estimated electric losses were min. 20%, this solar windows installation is currently running according to the predicted parameters.

For a summer sunny-day generation in excess of 1720 Wh (stored available energy), the energy production during the cloudy rainy days is typically seen at 900-1300 Wh per day. During much shorter winter days, we still store up to 1200-1300 Wh of energy daily.

The Warwick installation (approx. 25 m2) if it were all optimally oriented (on a North-facing non-shaded roof section), would have generated 1142 kWh per annum, as calculated using the same online NREL Calculator. This figure corresponds to the daily average of 3.12 kWh versus the current daily average near 1.37 kWh/day from the less than optimally oriented current configuration.

How much energy do ClearVue windows make?

A realistic estimate based on actual measured performance at Warwick Grove predicts generating approx. 70 kWh/day from each 1000 m2 of ClearVue windows installed. Annually, in excess of 20 MWh from each 1000 m2 of ClearVue windows in climates like Perth’s.