So there it is. We haven’t made it through the first week of post-Christmas work and loadshedding has already kicked in. That doesn’t bode well for the rest of the year – especially since the Mail & Guardian is reporting today that Eskom has less than three weeks before it goes bust.

What that means is that even if, somehow, you’ve managed to keep your head in the sand and hope loadshedding will simply go away, it’s time to start thinking about your option. The nuclear option – oh, how I’ve always wanted to write that – is a good couple of decades away from saving us, and fracking the Karoo for gas doesn’t seem to be the speediest or most attractive of our options either. Either economically or financially.

Nope. It’s time to take matters into our own hands. Decentralise the power grid. Turn into small scale providers ourselves. Find alternatives and keep the lights on.

It’s just about time to go solar.

Before you go looking for a smart new system powered by the sun, there are a couple of things that you probably should know – but most importantly, it’s not cheap.

In the short term, anyway.

You have to see it as a long term investment. The general price of photovoltaic (PV) panels is around is about R20 000 per kilowatt (kW) installed, and you’ll need to include some form of energy storage on top if you’re going to turn the lights on at night. The average household in South Africa draws between 3 to 5KW  of energy at the peak of its daily power consumption. That’s a number which can be brought down a lot if you cook on a biomass burner (aka the braai) and install a separate solar geyser. Even if you’re really careful and prepared to plan your week so that the dishwasher and washing machine aren’t running at the same time, getting the kW output up to a stage where it would become sufficient to run a home without, you’re likely to be staring a R100 000 system in the face.

Here’s what those in the business reckon a basic system would cost.

But a system that doesn’t have the capacity to store the electricity generated will only be of much use during sunlight. Adding storage capacity to the installation costs will set you back around 30% of the initial investment.

It might sounds like too much money to be sustainable, but crunching the numbers quickly reveal that it is more cost-effective to rely on a solar system during the day than what it is to get your power from Eskom.

“Assuming an installation cost of R100 000 initially and a performance life of 20 years, this system will produce about 6 000kWh per year and in 20 years it will produce 120 000kWh. This system will produce electricity at 0.84 cents per kWh as opposed to R1.20 to R1.50 from ESKOM or municipalities,” explains Sunny Morgan, CEO of renewable energy suppliers Enerlogy.

The reason solar is starting to make sense, says Morgan, is because it’s fallen to a point of “grid parity” – where photovoltaic panels are the equivalent or cheaper than buying that amount of electricity from Eskom. The average price per kWh (accounting for variations in tariffs over the years and sliding tariffs based on usage) from Eskom has almost doubled in the last five years.

The International Renewable Energy Agency, meanwhile, estimates that the average price of a while he points out the global price of solar panels has decreased by over 80% since 2008.

The design of solar panels has also been improved over the last couple of years, so the ones fitted to rooftops today have a performance guarantee is for 20 to 25 years. But when it hit the 25^th year, the panel don’t necessarily need replacing: by that time they will still be producing around 75% of the power it was originally designed to do.

Eskom, meanwhile, has been told it can push up prices by 8% annually at the moment. Assuming that trend continues (it might not, but then again it probably will), comparing the cost of Eskom energy against a solar system amortised over 20 years you get a graph like this.

But switching over to solar panels does come with its pitfalls, as Morgan points out that if you want to have any sort of power during Eskom’s loadshedding, you will definitely need to buy electricity storage capabilities – or a backup power source, such as a generator.

“It is erroneous to think that a grid-tied system without backup or storage will be of any benefit in a loadshedding or grid failure scenario,” says Morgan, “In order to get the full benefit of solar installation during loadshedding or grid failure it is imperative to have backup power, batteries or a generator. A grid-tied solar system will not work while the grid is down.”

The reason for that is that the South African grid isn’t designed to have electricity flowing both ways: if your solar panels are powering the same domestic ringmain as an Eskom cable you have to disconnect them during a power cut or power will start to flow back down the grid. Isolating solar onto a separate ring with battery backup for when the sun goes down means you can use your solar panels whenever the sun is up.

Without batteries, you’d need to plug your solar panels into the Eskom ring so that the public supply can take over when it gets dark. Really, storage costs and space to put batteries are what make solar impracticable for many people (plus the fact that few people live in one house for the 20 years necessary to make it economical).

In an interview with CNBC, however, futurist and senior fellow at the Institute for Ethics and Emerging Technologies Jamais Cascio said that while electricity storage batteries are very expensive, the prices will definitely be coming down as the technology gets better. Here in South Africa, we know at least two companies that are seriously investing in hydrogen storage, for example.

“The improvement of batteries will be fundamental to a revolution that will make any kind of living off the grid not just possible, but easy. The idea of energy off the grid really comes down to be able to generate it easily and be able to store it in volume,” Cascio said.

Morgan agrees, adding that South Africa has more than enough available sunlight to make it real option in the future.

“We are blessed with an abundant solar resource and we should take advantage of this resource in SA. Solar PV is cost effective and coupled with batteries it can be an effective solution to energy uncertainty.”

“It is a good idea to switch to solar to secure supply, to protect the environment by lowering your carbon footprint and reducing greenhouse gas emissions. The installation of a solar PV system with adequate storage is a no brainer.”

The big question, for us, is financing. The barrier to installing solar is the upfront cost, but if calculating the cost per month over 20 years works out to such good value, why aren’t there more banks offering home owners loans at a reasonable interest rate to make the switch? R100 000 or more is a lot of money to find for a solar system, but many households spend more than R1 000 a month with their electricity supplier and would be happy to pay less to a bank.

[Main image – CC by 2.0/John Gwynne]