Can you install solar PV without having a battery storage system?

For this week's ESI Africa column, I address a query often raised by people looking to invest in rooftop solar PV. Usually, the decision is influenced by the increasing occurrence of loadshedding (grid-connected power outages) and the rising cost of electricity tariffs.

The viability of solar power without battery storage

No matter where you reside, a solar power system is costly. It’s even more expensive when coupling the PV installation with a battery storage setup. So, the question is whether your solar rooftop PV can operate without storage.?

The short answer is yes, but only with an inverter. Well, it can work without an inverter but only where, for example, the unit is a standalone solar light that isn’t connected to the structure’s (home, office, outhouse, etc.) electricity board. Let’s explore this a bit more.?

I won’t deny that the cost of solar energy is declining. Technological advancements, economies of scale, and increased efficiency in manufacturing have driven down prices.

Supporting this narrative, the International Energy Agency reported the cost of solar PV electricity has fallen 89% in the past decade. Elon Musk, CEO of Tesla, emphasises this trend: “The cost of solar is gonna drop so much that it’s gonna be a no-brainer.”?

Regardless of how you feel about the billionaire, it’s easy to agree with Musk’s statement. This cost reduction benefits consumers and contributes significantly to the global shift towards sustainable and affordable renewable energy solutions.

However, in real terms, this steady pace has not influenced the cost of a solar PV installation for most people. The hefty financial investment needed is keeping many small to medium-sized businesses and the residential market from gaining a foothold in the clean electricity end-user market.?

Solar power and battery storage in the real world

To give you an idea of how costly it is, here is an example. Kenyan newspaper Sunday Nation reports how a coffee shop owner (you will know how much I love coffee from my article on the impact of climate change on coffee beans) installed a $10,000 solar energy system. That equates to about Sh1.6 million or ZAR188,000. What small businesses can afford this outlay? EsQoffee’s route to market was through a private investor, but this is not always an opportunity for everyone.

The newspaper article doesn’t say whether the system includes storage. Considering that the EsQoffee outlet still needs to be grid-connected, we can assume that the solar system includes battery storage. The café has invested in an off-grid system, which requires storage.?

So, adding to my initial short yes-answer, be aware that the answer is NO if it’s an off-grid PV system. There are two main reasons why battery storage is required for systems without grid connectivity. The reasons are, firstly, voltage and frequency stability and, secondly, energy storage.?

Why are these two reasons so important??

In off-grid solar systems, the sudden demand for power by AC loads can potentially disrupt the voltage and frequency of the electrical network within a home or business.??

Equipping solar inverters with control devices that swiftly adjust power output, maintaining stable voltage and frequency levels, counteract this challenge. While the critical prerequisite for this process is a steady voltage source at the input, which storage provides. This function makes batteries essential for off-grid solar systems.?

The other pivotal role of batteries in off-grid solar panel installations is energy storage.??

Since solar panels generate power only during daylight hours, off-grid homes and businesses will face power shortages during low sunlight irradiation times (such as cloud cover) and at night. An energy storage system, i.e., batteries, becomes indispensable to ensure an uninterrupted power supply from the solar modules.?

Ultimately, whether the solar power system includes battery storage is up to the person responsible for the payment. The cost is invariably the deciding factor. Fortunately, commercial banks have seen the market gap and are offering solar power loans, much like vehicle finance.???

Last year, I enquired about installing a home system. The rewiring cost put this outside our budget because the house is still on an old electrical wiring system. If you’re willing to divulge, please share with me the route your business or private home has taken, the cost, and how you financed it.??You might just persuade me to take the solar plus storage plunge.

What's next?

I am attending Solar Power Africa next week, 7-9 February, at the CTICC in Cape Town. This year's event is themed on Empowering Africa's Energy Future: Solar and Storage Solutions for Sustainable Development. If you spot me in the crowd, please do say hello.

Thank you for reading my weekly column.

Nicolette