+50% ZETDC Increase or Free Energy from Off-Grid Solar Water Heating Geyser

The Zimbabwe Electricity Transmission & Distribution Company (ZETDC) on Wednesday raised electricity tariffs by 50 percent, as it warned there would now be tariff reviews every month in line with inflation and currency exchange rate movements.

Power utility ZESA, the holding company of ZETDC, said earlier this week that its “sub-economic tariffs are by far the lowest in the region”, adding that it was now struggling to generate power or finance imports after accumulating liabilities of US$82.6 million.

ZESA said it owed millions to coal suppliers for its coal-powered power station at Hwange, and the Zambezi Water Authority for its hydro power drawn from the Kariba Dam. It is also battling to extinguish legacy debts with Mozambique and South Africa’s state-owned power utilities to unlock more exports.

Zimbabwe’s power generation remains depressed with ageing equipment at Hwange causing constant breakdowns while low dam levels at Kariba have reduced generation.

Zimbabwe lies within the tropics and has an average daily sunlight of 8.3 hours annually. It experiences a high elevation of the sun because of its tropical location, making it ideal for the use of geyser Solar Water Heating.

Hydro Electric Power operates at below capacity because of persistent droughts which have affected water levels at Lake Kariba and Tokwe and Mukosi dams. Thermal power generation is also affected by periodic breakdowns of generating equipment some of which is quite old. This means Zimbabwe has to import electricity from South Africa and Mozambique. Despite these electricity imports from neighbouring countries the supply cannot meet demand. There are punishing load shedding schedules which sometimes last as long as 18 hours a day.

According to figures from the Zimbabwe Electric Supply Authority [ZESA] electric geysers use up more electricity than any other appliance in the home, whereas off-grid solar water heating geysers provide hot water using energy from the sun which is plentiful and free.

Last year the cost of electricity went up significantly. The Zimbabwe Electric Supply Authority. ZESA did away with the single tariff that had been in place for over 10 years. They introduced a stepped tariff system and according to their website “the more electricity you use the more you pay per unit” as illustrated by the 3 consumption bands below. Below are the prices charged by ZESA as of  23rd September 2020.

Consumption BandsZWL$ per kWh
First 500.74
301 +6.92

At these prices the first 300kwh cost ZWL$715 after which the price per kW rises steeply to  ZWL$6.92. Considering that a lot of households use electricity for cooking, lighting, pumping their boreholes in addition to all other electric household gadgets means the energy units for an ‘electric geyser’ will be at the higher rate of ZWL$6.92 per kw.

Using the Thermodynamic formulae for calculating the amount of power (kW) required to heat a specific volume of water by a given temperature, we can work out what the annual costs of running a 160L and 300L electric geyser if it is on for 1 hour per day.

Formula: Pt= (4 x L x T) /3600 where {Pt=power used to heat the water; 4= a factor; L= Volume of water; T=Time and 3600 a given constant}. To heat water from a temperature of 10°C to 55° C the water temperature has to rise by 45° C.

For a 160L geyser the power consumption would be –  4 x 160 x 45/3600= 8kW.

For a 300L geyser power consumption would be – 4 x 300 x 45/3600=15kW.

The running costs of a 160L geyser (alone) at current ZESA electricity prices would be  – ZWL$6.92 x 8 per day x 365 =ZWL$20,206 per year.

For a 300L geyser (alone) the running costs would be ZWL$6.92 x 15 x 365 =ZWL$37,887 per year.  These costs are quite significant by any standard.

On the other hand, off-grid solar water heating geysers provide hot water using energy from the sun which is plentiful and free. Apart from the initial installation costs, solar geysers have low maintenance requirements, do not use or need any electrics to operate, have no moving parts that would get worn out and are super energy efficient. Why rent your energy when you can have it for Free.

Engineered solar thermal systems can deliver energy for many different purposes from domestic to commercial and industrial applications. The most common use is to deliver carbon free hot water for homes but can also be used for solar swimming pool heating and industrial process heat.

Invest here in a solar water geyser for your home, its a smart investment!

solar water heating