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I invested in solar but I'm disappointed - why?

By , co-founder and CTO of energy storage company REVOV
Africa , South Africa , 28 Feb 2022
Felix von Bormann, co-founder and CTO of energy storage company REVOV.
Felix von Bormann, co-founder and CTO of energy storage company REVOV.

It should come as no surprise that there has been a massive spike in interest and uptake of solar installations of various sizes. Load shedding and unplanned outages have affected businesses and households alike.

This has had a massive impact on businesses as well as households, and so many have decided to install various systems to try to mitigate the effects of the unstable grid. However, concerns about the environment have changed the way many, if not most, people see energy and this trend is going to continue accelerating. At a global and national level, renewable energy is gaining traction and even though South Africa has moved slowly compared to other countries, the horse has bolted.

With this in mind, many people have installed solar panels on the roofs of their homes but unless these installations have been carried out by knowledgeable companies, some people find the results to be somewhat underwhelming, which can, of course, be mitigated or even reversed with the right design, equipment and size investment.

Lithium iron phosphate batteries are the perfect fit for stationary storage solutions.

Why do you need batteries, you may ask? Because when there is no sun and the PV panels are not generating electricity, then the batteries come to the party.

Why does solar not run enough in my house?

The installed system may be under designed as compared to the load. A common installer mistake is to omit the daily energy required to recharge batteries. The weather may have an impact on the production of power - cloudy and rainy weather causes less production due to less sun. The solar panels may be installed incorrectly, for example in excess shade, or the panels are facing the wrong direction for maximum sun exposure.

Why do I run out of power when there's load shedding?

It is possible the batteries did not charge fully to 100%, and this may be because the incorrect energy profile has been set up or there is not enough PV installed in the system.

Another reason is that the load is too high for the system, for example, there is not enough inverter (or even, battery) capacity and there are too many appliances being used which drain the batteries. It may well be that the installation is designed under spec according to the load that is needed during load shedding.

Is there a way to have proper power when it's raining?

Solar panels can still work during rainy days however their production will be lower than usual. After a couple of days of bad rain, you can expect that the solar panels have not produced enough power to fill the battery completely and therefore you will have a reduced capacity, and need to be conscious of this.

To make sure there is enough power during bad weather, ensure that only essential loads are being used, and monitor your usage.

Why bother with lithium when lead acid is cheaper?

Lithium iron phosphate is the battery of choice in powering homes and businesses, and the battery of choice for stationary energy storage systems. These batteries are widely used in electric vehicles and so have a proven safety record. 2nd LiFe versions of Lithium Iron Phosphate batteries are comparable in price to lead acid packs that deliver the same output. Lithium Iron Phosphate batteries have a lifespan three times as long as lead acid batteries, have fewer safety risks and require negligible maintenance.

LiFe batteries tolerate considerable abuse and big variations in temperature and are significantly cheaper to keep charged up. Lithium batteries in poor DC systems tend to accommodate the system via the BMS (battery management system) and get “shaped” by the DC system to produce energy according to the operating parameters.

Lead acid requires maintenance to keep it working well and doesn’t last as long as the equivalent Lithium Iron Phosphate battery pack. The recharging of lead-acid batteries will be two to three times slower, drag over hours and hours rather than the quick one to two hour process with Lithium Iron Phosphate.

Lithium Iron Phosphate is a convenient and safer alternative to lead acid. It’s much more of an “install and forget” solution as you move off-grid and look to stop trying to depend on an unstable national grid power provider.

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