Conrem Energy

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Conrem Energy: Solar system overview and cost savings

How to reduce energy costs?

Water heating is generally one of the major energy consumption components in most residential type buildings – typically 40-60% of the total consumption (the percentages vary dependent on the use of air-conditioners, pumps, refrigeration).

“Solar systems” have two major application areas and types:

  • Thermal Solar systems – these utilise thermal energy from the sun to heat up water via flat plate collector panels.
  • Photovoltaic solar systems (PV) – which use sunlight and convert it to electrical energy with PV panels and inverters.

Conrem Energy’s Thermal solar system equipment, typically consists of the following major components:

  • Flat plate collectors.
  • Industrial, galvanised tanks manufactured by Conrem Energy, tailored for application. Tanks are galvanised both inside and out, as well as manufactured from thicker steel than competitors, to ensure tanks last well in excess of 5 years.
  • Circulation pumps when required.
  • Reticulation piping, manifolds and ring mains where required.
  • Insulation materials for the water storage and reticulation.
  • Control panels and systems where required.
  • Electrical back-up elemental heating systems.

Conrem Energy system design essentials

Based on over 30 years experience in the development of Solar systems, the team has determined that certain key issues need to be included in the design in order to achieve the desired savings in electrical energy costs as well as the required pay-back to justify the capital expenditures:

  • Optimised thermal mass of water in the design (if system design volumes are too small for the volume of consumed water, the system will not give the desired energy saving benefits. Both water volume and time to absorb thermal energy, play key roles in the effective retention of energy in the water mass).
  • Tank design and specification (tanks are made using steel shell thicknesses several times what some competitors use. The tanks manufactured, by our team, are galvanised both inside and out. This gives maximum performance of the tanks and a resultant attractiveness for long terms investment views on this technology with some tanks lasting as much as 34 years in service. Typically, in excess of 10 years is achieved historically from this approach).

Expected savings from Thermal solar systems:

International studies have shown that flat-plate collector systems, when properly designed can achieve the following savings for a typical +-2m2 flat plate collector: 5.4-11.2 KwH/ day.

The team, over more than 30 years, has observed from both their own and independent data generated from clients, that a typical average of 7.2 KwH/day* per collector saving can be achieved, which is in line with international data for this region on the east coast of South Africa.

*Note that several factors will affect the performance of a system that are not elaborated upon in this overview.

Depending on the price of electricity paid by our clients, this number can be used to determine the expected savings for the system cost. Payback periods typically vary from 2-5 years.

Actual results observed: large building complex    

Actual results observed: large building complex

The specialist team with an installation


Historical results from installations completed

Case 1Retirement Home, Beach Front, Durban. Actual data from client

The blue line is the current total electrical consumption using the heat pump. The red line is the electrical consumption after removal of heat pump and installation of solar thermal system. The green columns show daily savings. 

Case 2Family Hotel on the South Coast: Electrical consumption: Before with heat pumps and after a properly engineered solar water heating system installation.

Below is actual data supplied by the client with before and after measurements.