Solar PV systems are becoming increasingly popular in domestic homes and commercial businesses, as sustainable practices become more commonplace and we are more active in pursuing energy saving initiatives. The testing and inspection of solar PV systems is critical, not just for safety and compliance purposes, as with any electrical installation, but also in terms of monitoring the performance of the installed system.
Why is solar PV performance so important?
The justification for investing in solar PV systems is usually based on the reduced energy consumption that results. So a user can measure how much energy costs are being reduced by using self-generated electricity rather than electricity from the national grid, and compare this to the initial investment. Over time, you should find a point where the money saved exceeds the money spent on the solar PV system, and this is the return on investment. Naturally, it is important that we can monitor and analyse how the system is performing so we can see if we are getting the results we expect and that the return on investment is on course to being met as predicted.
How is a solar PV system set-up?
A solar PV system converts the sun’s radiation into usable electricity. It is an installation ranging from 1000 volts to 1500 volts, and as such safety and compliance is very important. A typical solar PV system consists of:
- PV cells – the actual panels, which can be single or connected in parallel as a series of panels. These convert light into DC electricity using semi-conductors.
- Inverter – this converts the DC electricity into AC electricity usable in commercial and domestic properties.
- Battery – this is able to store electricity for later use.
How do we test the solar PV system performance?
In order for a solar PV system to perform to its design brief, it first needs to be installed and commissioned properly. To do this we would use:
- Multi-function tester – this checks the basic electrical safety and performance of the system, such as the insulation resistance of the single module or a series of modules as well as the polarity and continuity of the conductors.
- Commissioning checker – this provides every test that is necessary to confirm the safe and compliant installation of the system, including an insulation test, continuity test and functionality of the connections as well as the strings in a photovoltaic field. This analyses the performance of the PV field under operating conditions, ie. when connected to the inverter.
During operation we need to monitor how the solar PV system is performing to confirm it is absorbing radiation as it should be and generating the electricity that it should be. We can do this using:
- Irradiance meter – this would be used initially to identify the best location for the solar panels in a home or workplace, but essentially, this instrument measures the irradiance in different locations so that you can choose the position that optimises the available sunlight. You should periodically check this to ensure that the expected irradiance levels are consistent and sufficient.
- Curve tester – this instrument measures the solar I-V curve and analyses the characteristics of the semi-conducting devices by measuring the current and voltage at multiple points.
- Digital multimeter – this provides a DC voltage measurement up to 1500 volts.
At Test Instrument Solutions we can supply all these different types of solar PV system test equipment and advise on the types of testing you need to undertake to ensure maximum performance of your solar PV system, so contact our team today.
Video Demonstration
Below is a video on our product TIS PV ISOTEST (Solar PV Multifunction Performance Tester):
Please note that this section is for information purposes only. Anyone using equipment referred to in this section must be suitably qualified and/or experienced within the respective field. If in doubt before use, please consult a qualified electrician or engineer & thoroughly read all instruction booklets.