If you have been living under a rock this might be the most random article you have come across on this site. Recently it was revealed by the Zimbabwean Standard that senior government officials, ministers, army generals, chiefs and other bigwigs were in the process of installing solar power in their homes. These systems are being installed at the taxpayer’s expense at a cost of about US$14 000 per house and around 100 were going to be installed. That adds up to an astounding US$1.4 million dollars. But is this a fair cost? How much does a 5-kW solar system cost to install in Zimbabwe?

Senior government sources said a local company (name supplied) has been contracted to install a 5 kilovolt (Kva) solar system at a cost of US$ 14 000 each for top chefs who include ministers, senior government officials, commissioners and army generals. This publication established that a full package of the 5 Kva solar system, which consists of accessories and labour, costs between US$3 000 and US$5 000 but government will be paying US$14 000 for the same service — a 200% inflated price

The Standard’s report on the issue.

Some time ago I wrote a Zimbabwean solar power guide for dummies on Techzim. The articles are a tad bit out of date and so I am in the process of writing another updated series. What has not changed since, 2015, are the frequent planned power cuts we have to live through each day. It is rather disheartening to note that it seems that, rather than solve these issues, the higher-ups in government are choosing to insulate themselves from the power cuts at the taxpayer’s expense. Anyway, this is article is aimed at being informative rather than being a general complaint on government policy so let us get to it.

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In general, a solar power system consists of the following:

  • Power panels that generate power when they are exposed to the sun
  • A charge controller that converts the power from solar panels to a voltage and current that can be used to charge batteries.
  • A battery to stores power and ensures that the solar power system is able to supply power during times when there is no or too little sunlight or there is a peak in demand that goes beyond what the solar panels are generating
  • An inverter that converts DC/battery voltage to AC power. Most household devices were designed to be used on the grid with AC power. An inverter allows those devices to be used on a solar system.
  • Cables, clips, brackets and other accessories including switches, lights etc. These tend to cost about US$200 at most.
  • Labour. Most installers charge about a 10%-20% markup as an installation fee. The most expensive ones go to around 30%

Having said that let us look at the prices for these various items:

  • A 5kw solar system usually uses 330W-450W solar panels. Each costs US$150-US$210 according to our latest price survey
  • Most inverters on the market double as MPPT charge controllers and are often hybrid. Depending on the brand of the inverter being used a 5-kW inverter costs around US$450-US$2 500 with Must inverters being the cheapest and Victron Energy Inverters being the most expensive. Low-frequency inverters are rare in Zimbabwe and it’s almost certain these are not the ones being used.
  • 5-kW systems use Lithium-ion batteries at least. For efficiency reasons, these systems tend to be 48V in nature. Each 48V 100AH battery costs around US$1 200 if brand new and about US$800 if it’s preowned and refurbished. You can bet the big chefs are using brand-new batteries. After all these guys scoff at ex-Jap cars as inadequate for them.

Cost estimation

ItemBase SystemMedium SystemPremium System
Solar Panels6×450 W panels=
US$1 260
8x450W panels=
US$1 680
13*450W panels=
US$2 730
Invertor5KW Must Invertor=
US$500
5kW Growatt Inverter=
US$700
5kW Victron Energy Inverter=
US$2 300
Batteries1x48V 100AH preowned Lithium Ion Batteries=
US$800
4x48V preowned Lithium-ion batteries=
US$3 200
6x48V 100AH brand new Lithium-ion batteries=
US$7 200
AccessoriesEstimated=
US$200
Estimated=
US$200
Estimated=
US$200
LabourEstimated=
US$500
Estimated=
US$1 000
Estimated:
US$1 500
Total CostUS$3 260US$6 780US$13 930
Nominal Units21.6 kWh28.8 kWh50 kWh
Autonomous Days0.511-2
Cost breakdown of systems on the market

NB

  • Most solar systems based on components are within 10% of our estimations above. Costs can vary because for example cheaper or more premium solar panels can be used, labour costs vary, battery prices vary, transport costs etc. For example, you can sweet talk your installer and pay just US$3 000 for the base system or you can ask for a cheaper LC Star inverter and pay a price as low as US$2 500
  • Most of these systems are based on consumption/power requirements. Base 5KW systems generate about 15 kWh to 25 kWh of power, medium systems produce around 30 kWh of power while premium systems are rated for 50 kWh. This is based on an assumed 8-hour sunny day. Most systems are about 70% efficient. 5kW inverters are very wasteful and can consume about 150 Watts of power on idle
  • Autonomous days refer to the days a system can power full load requirements without sunlight. Base 5kW systems bank on the fact that most of the time you are not using a lo of power and the sun is shining consistently. You might have to switch fridges at night for example or charge the battery using ZESA at night. Most inverters are configured to automatically do these things.

Conclusion

We are not privy to the exact specifications of the systems the government is having installed for the bigwigs but for a premium 5-kW system US$14 000 is not really an inflated price. In fact, such systems can cost more if you add more batteries and solar panels although in such cases it’s almost always sensible to upgrade the inverter as well to power more loads. At continuous load, a 5-kW system can produce 120 kWh of power although homes never consume that much power. Such a theoretical system could cost tens of thousands of dollars. It is therefore premature to say that the costs are highly inflated. It’s possible the big chefs are simply demanding premium parts where basic ones would do. Given our “Look East” policy cheap Chinese inverters and batteries should be installed as they are just as good as overpriced western solar parts which are often made in China anyway.