The “electron economy” refers to a global shift towards using electricity as the main energy carrier. The term was coined in 2006 by Ulf Bossel, a fuel cell engineer and entrepreneur. In 2007, Michael Hoexter neatly summarized the electron economy concept based on Bossel’s ideas in a blog article that is unfortunately no longer accessible on the internet:
“Electricity, it turns out, is a highly efficient and flexible carrier of energy.
Electric motors are highly efficient energy conversion devices (85 to 95% efficiency vs. 15-25% for typical gasoline engines).
Newer (hydrogen) and older competitors (fossil fuels) to electricity are less efficient and/or have environmental drawbacks.
We already have over a century of experience with electricity.
Renewable energy sources (wind, sun, tides, geothermal heat) can usually most efficiently be converted to electricity rather than to other carriers like biofuels (solar cells, though currently expensive, are up to 400 times more efficient in converting sunlight into energy than plants).
We should focus on transitioning to a largely electric energy infrastructure with the probable exception of fuels for aviation and shipping, where biofuels will have advantages.
Increasing the energy-to-weight ratio and usefulness of electricity storage devices (batteries, etc.) is largely a technical and economic issue that will change for the better, as has been already witnessed in the portable electronics industry. Setting today’s battery capacity as an upper-limit to what can be done with batteries and electricity storage is a political move, not based on reasonable expectations for even modest technological improvements.
Even an economy fueled in part by fossil fuels can be made less environmentally damaging by increased use of electricity as an energy carrier and using electric energy conversion devices like electric motors.Using fossil fuels in highly efficient fuel cells and combined-cycle power plants to generate electricity is second-best to electricity generated by renewable sources but may play transitional roles to a carbon-neutral economy.”
The above seems to be quite prescient today (about 10 years later), in light of the rapid growth in recent years in renewable and electricity storage technologies (such as batteries and fuel cells). You can learn more about the electron economy from a slideshow by Prof. Robert Cormia that you can find here.
The International Energy Agency indicated just last month that it has significantly increased its five-year renewable growth forecast, following a record year for renewables in 2015. For the first time, more than half the new power capacity added globally in 2015 was renewable. Some staggering numbers:
About half a million solar panels were installed every day in 2015
In China, on average two wind turbines were installed every hour in 2015
The spectacular growth in renewables is partly due to regulation and partly due to the rapidly decreasing cost. It is also driven by commitments to move towards deriving 100% of their energy use from renewables by large corporates such as Walmart and Amazon.
On the electric vehicle front, the 2016 Paris Motor Show confirmed a clear shift towards electric vehicles (EVs) by most major car manufacturers. And in a first for Africa, the City of Cape Town will be adding 11 electric buses to its MyCiti Bus Rapid Transit fleet!
Even the South African government is starting to feel the winds of change blowing: in a very recent presentation on the latest draft of the Department of Energy’s Integrated Resource Plan, nuclear build is now pushed out to come online only in 2037 (vs the previous 2029), and renewables are given a bigger role. The draft will be published for public comment.
The Department of Energy’s own Ministerial Advisory Committee on Energy recently released a report that indicated that the least cost scenario for South Africa’s future energy production includes NO new nuclear, and mostly renewables with natural gas as peaking capacity. (You can read more on the analysis here, and find a detailed presentation here.)
While SA seems stubbornly focused on coal (including new private coal-fired power stations), gas and nuclear, Germany is forging ahead with its bold moves to transform into a country with 100% of its energy provided by sustainable and renewable sources.
Already a world leader in incorporating renewables into its national grid through its ‘Energiewende’ programme (with renewables at one point in May 2016 reaching over 90% of the total German power consumption), Germany is not slowing down. In early October, Germany’s Bundesrat adopted a resolution to ban petrol- and diesel-powered vehicles by 2030!
Meanwhile, in South Africa (a country with an embarrassingly rich solar resource compared to Germany), Eskom complains of problems managing and integrating a lowly 2.2% renewables (solar and wind – as of first half 2016) into the SA national grid, and has even signaled an unwillingness to sign further power purchase agreements (PPAs) with independent power producers. (Recently, the SA Wind Energy Association, SAWEA, has lodged an official compaint with NERSA, the National Energy Regulator of SA, over Eskom’s refusal to sign further PPAs.)
Yes, renewables are intermittent and unpredictable (actually predictably unpredictable and eminently manageable over bigger time scales and geographical spreads!), but through good planning, judicial use of energy storage (the cost of which continues to come down at a brisk pace) and distributed generation, these problems can be overcome and renewables can deliver a very high percentage of total energy production. (According to a July 2016 CSIR and Fraunhofer study, up to 65% solar and wind energy generation share can be achieved in South Africa without any additional storage or significant excess energy / curtailment!).
Experiencing pushback from National Treasury about the immense R1 trillion or more bill for the planned nuclear deal, the Department of Energy has now announced that Eskom will finance the whole programme itself, neatly bypassing the need for Treasury approval. The question is: if (when?) Eskom gets into financial trouble later on, who will have to bail them out? Treasury may be forced to do it at that stage to keep the lights on. (And this means WE, the taxpayer, will ultimately pay.)
These troubling developments are happening at the same time as SA is being praised (deservedly) as a world leader in renewable adoption (see e.g. articles here, here and here). As always we seem to manage to be the best and the worst at the same time! What is certain is that interesting times lie ahead in the business of energy in South Africa…
PLEASE NOTE: This article is from 2015. Current status (2021): If financed via a home loan, solar PV plus storage is less expensive than buying electricity from your municipality in South Africa. According to this research by Sustainable Energy Africa, this was already the case in 2019 for middle-income households.
With the price of solar PV (photovoltaic) panels dropping by more than 10% per year, and Eskom seeking double digit increases for the foreseeable future, when can we expect to see the cost of residential solar PV and battery storage systems to drop below the cost of grid power from Eskom?
We did a simplified calculation to obtain an estimate of when this might happen… And it seems like it will start making financial sense for South Africans to switch within the next 3 years! Thereafter, the financial case for switching will just get stronger every year…
A major barrier to solar PV and battery storage systems is the upfront capital cost. But this could be financed by your bank, and you would be assured of a fixed electricity price for 20 years, compared to continually rising electricity costs if you are tied to the grid. Also, you would be completely free from loadshedding!
How we calculated:
We assumed a typical residential electricity usage of 900 kWh/month, at a current price of R1.40/kWh.
We estimated a current cost of a solar PV + battery storage solution to go off-grid at R200 000, plus an additional R30 000 for a solar geyser and gas oven.
We assumed a 10% increase in Eskom prices and a 10% decrease in solar PV + storage system prices per year. (This is conservative, as discussed above.)
We assumed a 20 year payback period and 10% interest rate on the loan to finance the solar PV + storage system.
Footnote: The graph plots the fixed monthly instalment that you would have to pay if you bought the system in the year as indicated. The instalments over the 20 year period would of course be constant. (So if you bought the system in 2015, fixed monthly instalment would be around R2 200/month over the 20 year period, whilst if you bought it in 2018, fixed monthly instalment would be around R1 600/month over the 20 year period.) Even if you bought the system right now (with the R2 200/month instalment), you will start saving by around 2020, meaning that for at least 15 years subsequently you will be paying less than what you would have if you were still on the grid (and every year the savings would increase due to the increasing price of electricity)…
Indeed! This brings us to the issue of load shedding.
Load shedding is when electricity supply is intentionally interrupted or reduced to avoid excessive load on the generating plants. Whilst it is very disruptive (as we all know!), it is preferable to a total collapse of the electricity supply grid, which will have disastrous consequences for the country. Should the demand be allowed to exceed the supply, it could very well happen and it would take a week or longer to get the grid online again.
2020 Update notes:
1. Please note that this article was written in 2015. Some of the recommendations might be outdated. For example, the price of lithium ion batteries have dropped dramatically since 2015 and have now become a viable alternative to lead acid batteries, with superior life, efficiency and general performance.
2. Please note that PowerOptimal does not sell or install inverter-based solar photovoltaic systems or battery backup systems. This article is provided for general information as a service to the public and not as marketing for our products. (We do manufacture and sell the Elon solar PV water heating system – this is a unit that allows direct connection of solar photovoltaic modules to a standard electric geyser, without an inverter.)
“If it weren’t for electricity we’d all be watching television by candlelight”
When a software glitch allowed such an imbalance to develop in 2003, the entire North-eastern and Midwestern United States and the Canadian Province of Ontario were blacked out, which left 55 million people without power for more than a week. A lack of alarms left operators unaware of the need to redistribute power after overloaded transmission lines hit unpruned foliage. Even in a technologically advanced country like the United States it can happen.
The first thing we need to realise is that load shedding will be part of our lives for several years to come. The second thing to realise is that it will get worse before it gets better. The next thing to realise is that we have no choice but to manage the situation according to our own specific needs.
Some of us could quite happily go without Sewende Laan, the Premier Soccer League and the Internet for several hours per week. For most of us though, a power failure not only spells inconvenience but a serious financial impact. Many small businesses face financial ruin. Business continuity is critical.
Backup power options for load shedding
If you cannot live with load shedding, your only alternative is to use stored energy when the lights go out and you really only have two choices, namely a generator or an inverter/ battery system.
What is an inverter? Basically it is an electronic or electrical device that changes DC (direct current) into AC (alternating current). It is required for when you want to use a battery storage system for backup power to your home or business, since the batteries deliver direct current and your devices / appliances run on alternating current.
In most cases, inverter/ battery systems offer superior performance and significant cost savings when compared to generators. Considering the efficiency of modern, solid state inverters, generators have definite drawbacks in several areas.
Most importantly, many body corporates, home owners associations, business parks and other landlords will not allow generators to be used. You can imagine the noise and smell when 200 generators start up in a complex.
The initial cost of a generator might be less expensive than an inverter system, but in the long run they are far more costly when you consider running costs and maintenance.Generators require constant attentionto assure proper operation. The oil needs to be changed regularly and other maintenance performed. It is also highly recommended that if a petrol generator does not run for more than 30 days, that the fuel is drained and the carburetor run dry. Nobody wants to go outside at night and perform a fault finding ritual when the generator fails to start.
Buying a cheap unknown brand of generator is penny wise and pound foolish. Very few are supported and even a minor unobtainable spare part could leave you in the dark once again. Connecting your expensive equipment to a unit with dubious or compromised circuitry may very well be a perilous exercise. Also, if you believe everything you read, better not read the spec sheets of some of the cheap imports.
With the ever increasing price of fuel, running a generator could become prohibitively expensive. And nobody likes the noise and fumes.
Fuel storage can be a nuisance as well. Apart from the fire hazard and regulatory problems, petrol cannot be stored for more than a month or so. You need to rotate your inventory on a regular basis to avoid problems.
An important consideration is the seamless transfer of power of the inverter system, which is impossible to achieve with a generator. Even with the fastest automatic and remote start facility, there will always be a delay of several seconds before the power comes on. By that time you might have lost important data on your computer or, even worse, you might have lost the plot of the soapie you were watching!
Having said all that about generators, an inverter/battery system is not the be all and end all of standby power. There are several disadvantages, like the energy storage limitations of the batteries as well as their expected life, which is generally between 5 and 7 years. Initial cost is an important consideration but it is for the most part justified by the preceding reasons.
Even more so than with generators, the bandwagon is overcrowded with opportunists looking to make a quick buck. If you are on a limited budget, rather buy a quality inverter of the size you prefer with fewer batteries initially. You can always add batteries later on but if you buy a 1 kW inverter with 3kW written on the package, you might as well go and play the lotto. At least you will have a chance of getting value for your money.
What about Solar, you may well ask. Well, the truth is that if all you are trying to do is bridge the gap between power outages, Solar is not the answer. The inverter/battery system does not generate anything. It simply stores and provides energy when needed. Significantly, mains power is still by far the cheapest energy you can buy today, in spite of the drastic Eskom price increases. If, however, you want to become less dependent on Eskom power, Solar might be an option but it is still very expensive. All the same, that is a discussion for another day.
What size inverter/battery system is appropriate for my household or small business?
1 to 3 kilowatt inverter/battery systems are the most popular for households and small businesses. Bigger systems generally require dedicated designs by competent engineers, so we will focus on the smaller systems.
Although it is technically possible to design a system that can pick up the entire electrical load of a household or business, it is totally impractical because of cost. Therefore high consumption items like geysers, washing machines, heaters and even kettles should be avoided to keep the size of the inverter down and limit the number of batteries. Since our aim is simply to survive load shedding, it is not too difficult to find alternatives for these energy guzzlers. Computers and TV sets do not do too well on candle power however!
To illustrate what is achievable, typical examples of the three most popular systems give a good idea of what is realistic. The figures in the tables below are approximate. The actual power consumption of your household appliances or office equipment may vary considerably from the figures in this table. Before you do a final load calculation, we strongly recommend using an electricity usage monitor to establish how much electricity an appliance is using. They are simple to use and cost around R750.
1 Kilowatt System
Rated at 1000 Watts, the system can typically back up the systems below. However, it does not mean that it can sustain the full load all the time. That will be like driving your car flat out all day long. A constant load of about 80% as depicted in the example is sensible.
The system now runs at 80% but a photo copier or fax machine, which operates for a limited time could be used in addition. Should you want to operate your garage door (750 Watts), some of the other loads will have to be turned off for a short time while the door operates. It will however, not accommodate boiling water in a kettle (±2000 Watts) because it is way above the system’s 1000 Watt rating.
Flat Screen TV DStv Decoder or PVR Stereo System Desktop Computer LCD Computer Monitor Modem Alarm System 5 Lights Total
Rated at 2000 Watts, the system can typically back up the systems below. Even though the total Wattage exceeds the 2000 Watt rating a maximum constant load of about 80% (i.e. 1.6 kW) is recommended. Some loads such as a microwave or printer are used for a short period only and will not put an excessive burden on the system.
You will obviously not use the microwave while something is being printed and it is a good idea to turn off the computer or the TV before using the microwave.
Flat Screen TV DStv Decoder or PVR Stereo System Desktop Computer LCD Computer Monitor Modem Alarm System 10 Energy Saver Lights Fridge Microwave Inkjet Printer Total
Rated at 3000 Watts, the system can sustain most household appliances with the exception of high power consumption items like the geyser, stove, washing machine, dryer, air conditioner etc. It will also keep a small office with several computers, printers, copiers etc. going. Typical use is depicted below.
Flat Screen TV DStv Decoder or PVR Stereo System Desktop Computer LCD Computer Monitor Modem Alarm System Surveillance Camera Electric Fence 4 Security Lights 10 Energy Saver Lights 15 LED Downlights 2 Bedside Lamps Alarm Clock Cell Phone / iPad / Laptop Charger Fridge Freezer Total
A number of the following appliances may be used, provided some of the loads are turned off to make provision for the higher consumption. The total consumption of 3000 Watts may be exceeded within limits for a short period because the inverter system has built in safety margins and will not be damaged. However, if the safety margins are exceeded the system will automatically turn off to protect itself. PowerOptimal’s Powerguard® Peak Demand Management system could be employed to manage these tasks automatically and will ensure that limits are never exceeded.
Microwave Toaster Vacuum Cleaner Electric Iron Inkjet Printer
What type of installation is appropriate for my inverter/battery system?
There are essentially three different ways of employing standby power systems. For 1 – 2 kW systems, it makes sense to use Version 1 or 2. From 3 kW and above, Version 3 with automatic switching could be a serious consideration. Systems larger than 5 kW require a site inspection and a dedicated design.
Version 1
The inverter and batteries are contained in a steel cabinet, which is fitted with a standard 15Amp plug outlet. Castors make the unit easily movable, but it is not designed as truly portable because the batteries are heavy and the weight could be considerable. It is typically used in the vicinity where it is required or with an
extension lead.
Version 2
The inverter unit is stored remotely and its output extended with its own cable via existing electrical conduit or surface mount to dedicated plug outlets that are completely isolated from the standard wiring. Potential problems with this solution are lack of space in the existing conduit or unsightly surface mounted cables.
Version 3
By employing the PowerGuard® DPM 30 – 8 Switcher, the inverter is permanently wired to the distribution board with minimal disruption during installation and present wiring remains untouched.
Unlike far too many risky installations, this perfectly legal connection complies with all regulations. Since it is impractical to use an inverter that is capable of picking up the full load, the PowerGuard® switcher ensures that high power consumption loads like the geyser and stove are turned off instantly during a power failure. With bigger units of 3kW and above, most other circuits like lights and plugs remain powered. Before installation, the client decides what should continue working during a power failure.
While we are on the topic of using existing wiring, a note of caution. Be very aware of wiring directly to your DB without a change over system that automatically and completely isolates the mains while running on the inverter. This is a serious fire hazard and while the electricity police will not come around and fine you, the insurance assessor will certainly take a keen interest in the wiring in the case of a fire damage claim.
What about battery types and sizes?
Although it is critical to use a high quality inverter capable of sustaining the design load, the batteries should also be of similar quality and of sufficient quantity. A bank of batteries with a combination of parallel and series connections provides the reservoir for the energy that has to be stored and later released when needed.
High performance lead acid batteries are usually used but they are not of the automotive type. While they are of similar construction, they are designed to withstand many more charge and discharge cycles and can also be deeply discharged. Known as a deep cycle battery, they can be cycled down to about 50% charge without incurring any damage. At that depth of discharge most of the potential energy had been extracted from the battery making them very useful for this application.
There are many varieties on the same theme ranging from the well known wet cell that requires regular maintenance to the more recently developed lead crystal with far superior performance and no maintenance whatsoever. As with all good things the superior performance naturally comes with a superior price.
The Sealed Maintenance Free Battery is reasonably priced and for that reason one of the more popular types. As the name suggests, it is to a large extent maintenance free, but the chemical reaction produces Hydrogen and Oxygen, which could form an explosive mixture. For that reason, these batteries cannot be used in a confined space and must be installed outside where it is well ventilated. They are generally about 35% cheaper than AGM batteries, which is the next step up.
In AGM (Absorbent Glass Mat) batteries, the electrolyte is mostly absorbed in glass fibre. This type of battery is entirely maintenance-free and there is no gas formation with normal use. Not requiring any ventilation, these batteries can be installed anywhere.
Batteries are rated in Amp Hour (Ah), which is a measurement of the amount of current it can supply over a certain period. They are rated over a period of 20 hours, which means a 100 Ah battery will supply 5 Amps over that period.
Simply put, the more Ah you have, the more capacity you have and the longer your system will produce power before the batteries run flat. To calculate the number of batteries required you may use the following rule of thumb. You need about one 100Ah battery per 1kW per hour. In other words if you have a 3kW system that should last for 4 hours you need 12 X 100 Ah batteries. 3 (3kW) X 4 (4 hours) = 12.
How can I contribute to reducing load shedding?
In spite of having alternatives for the times when the lights go out, all of us can contribute to limit load shedding to a minimum. We are in the middle of an energy crisis and each and every one of us needs to modify our lifestyles to accommodate this harsh reality. Here is what to do:
Switch off your geysers, electric heaters and pool pumps from 17h00 to 21h00 every day.
Switch off unnecessary appliances and lighting.
Consider alternative heating solutions (gas stoves, gas heaters, solar geysers, etc.).
Switch to CFL and LED lights.
Turn off anything that consumes standby energy (TVs, DVD players, computers, cell phone chargers).
Respond to the Power Alerts and Power Bulletin.
After all, saving electricity is a BRIGHT idea!
2020 Update notes:
1. Please note that this article was written in 2015. Some of the recommendations might be outdated. For example, the price of lithium ion batteries have dropped dramatically since 2015 and have now become a viable alternative to lead acid batteries, with superior life, efficiency and general performance.
2. Please note that PowerOptimal does not sell or install inverter-based solar photovoltaic systems or battery backup systems. This article is provided for general information as a service to the public and not as marketing for our products. (We do manufacture and sell the Elon solar PV water heating system – this is a unit that allows direct connection of solar photovoltaic modules to a standard electric geyser, without an inverter.)
Recently we learnt that Eskom has requested another 9.58% tariff increase from NERSA for 2015, on top of the 12.69% already approved for this year. More recently, it has emerged that Eskom is requesting what is called a “selective reopener” for 2016 and 2017 as well. In particular, it seems that Eskom is looking for an additional 9% increase in each of 2016 and 2017 – i.e. 17% increases in tariffs in both these years instead of 8%/year.
People know the power of compound interest (exponential growth!), and so it is interesting to have a look at where Eskom’s (effectively South Africa’s) electricity tariffs have come from and where they seem to be going.
The infographic below shows the Eskom tariffs from 1988 to 2015, plotted against CPI (Consumer Price Index) or inflation over the same period. It also shows projections up to 2017, based on the additional increases requested by Eskom, and based on SARB’s inflation projections.
Note: The infographic depicts overall average increases – actual increases will be different for different types of consumers (residential, commercial and industrial) and will vary between municipalities.
Looking at the graph, the following can be noted:
In the period from 1988 up to the 2008 electricity crisis, electricity tariff increases did not keep tread with inflation. This was partly due to government policy to keep electricity tariffs as low as possible for poor communities, but also due to Eskom having an oversupply of electricity (in the 1990’s) and not investing in new capacity (in the 2000’s).
Between 1988 and 2007, electricity tariffs increased by 223%, whilst inflation over this period was 335%.
From the 2008 electricity crisis onwards, there is a clear and sharp inflection point for electricity tariffs in South Africa. From 2007 to 2015, electricity tariffs increased by 300%, whilst inflation over this period was45%. Thus electricity tariffs tripled in 8 years.
If the additional increase for 2015 (another 9.58% on top of the 12.69% already approved by NERSA) is approved, this will mean that the total increase in electricity tariffs from 2007 to 2015 would be 335%.
If the additional increases for 2016 & 2017 (another 9%/yr on top of the 8%/yr already approved by NERSA) are approved, this will mean that the total increase in electricity tariffs from 2007 to 2017 would be 495%, compared to 74% for inflation over the same period. Thus electricity tariffs would have increased 5-fold in 10 years.
We need to keep in mind that SA’s electricity is still not very expensive when compared to the rest of the world or even Africa. E.g. in 2014, Uganda, Namibia and Ghana had tariffs more than double that of South Africa. However, the problem is that the South African economy has structured itself around cheap electricity, and it will be costly to change the way things are done (behaviour) and change over to more energy-efficient infrastructure.
The SAIRR recently published a report projecting that Eskom will have another 18 000 MW supply shortfall by 2030, if our GDP grows by 3%/yr. This is in addition to Medupi, Kusile and Ingula. (See this Fin24 summary of the report.) To add insult to injury, Standard & Poor’s has just downgraded Eskom to junk status.
Considering the above, it is safe to say that we can expect to see over the next several years: (a) a continuation of the current electricity supply shortages (read: load shedding); and (b) higher-than-inflation electricity price increases. We will all need to start thinking about how we can contribute to reducing demand and minimising the impact of the supply constraints.
By employing the PowerGuard® DPM 30 – 8 Switcher, the inverter is permanently wired to the distribution board with minimal disruption during installation and present wiring remains untouched.
