Tag Archives: Solar PV

Earth, Wind, Fire, Water & Tyres


Grey Green recently completed a comprehensive energy audit at one of the largest tyre manufacturers in Africa. Our team investigated all energy and material flows. Excellent savings opportunities were found on:

  • Air compressors, plus compressed air distribution and use
  • Boiler, steam distribution and use
  • Effluent
  • Lighting
  • Materials handling
  • Solid waste
  • Water heating

The sixteen best savings opportunities gave payback periods between immediate (no Capex required, just improved control or maintenance) to ~3.9 years, with the average at less than 2 years. These were also quantified in terms of reduced carbon dioxide emissions and decreased carbon tax liability.

Annual financial savings were several millions of Rands.

The tyre company management shall also be able to use our Scenario Planning Tool to:

  • Graphically compare the savings produced by each savings opportunity
  • Decide when each opportunity should be implemented

Scenario Planning Tool

Grey Green also conducted pre-feasibility studies on various sources of renewable energy:

  • Earth – Biogas, from anaerobic digestion of locally sourced organic matter and biomass as a boiler fuel
  • Wind – Wind turbines opportunities in the region
  • Fire – Solar PV (i.e. photovoltaic) and solar water heating
  • Water – Hydro-electric options available.

As expected, the renewable energy opportunities have longer payback periods than energy efficiency opportunities, but once factory efficiency has been maximised, the only way of reducing energy costs further is by producing one’s own energy from renewable sources.

Bonnievale 75MW Solar Farm

Grey Green was appointed to assist the project developers with the topographical modelling of the planned 75MW Solar PV plant layout onto the existing digital elevation model. This included high-level plant designs and 3D sketches of final appearance on the actual landscape near Bonnievale, which shall be used in the EIA process.

Our first export!

Close the Gap has commissioned Grey Green do a second DigiTruck. This time it will be sent, by sea (and road freight) to Kinshasa in the Democratic Republic of Congo.

The challenges faced once again were “How are we going to deliver a fully functioning off-grid IT lab to the DRC?” To keep logistics costs down, a revolutionary design was conceived by Grey Green that allows for no changes to the external dimensions or structural integrity of the container. To further reduce installation costs, the system was pre-engineered, mounted, wired and tested locally such that it was ready for a simple DIY installation in half a day once it reaches its destination by the recipient community members.

Grey Green has proven that it is now able to deliver containerized off-grid solar PV solutions to anywhere in the world.

Do you need electrical power in remote and isolated areas?
Do you need a self-sufficient mobile clinic, office or classroom?
We have a sustainable energy solution ready for you…

Helping Close the Gap


Holland-based NGO, Close the Gap, approached Grey Green late in 2015 with a challenge…

Can you design an off-grid PV system to cater for the IT class that seats 18 students?
Can the system be transported all over South Africa?
Can you make the system go from disassembled to operational in under one day?
Can you design it so that anyone can assemble the system?

Grey Green took on the challenge and delivered a system that now provides education to students of all ages in Langa, Western Cape.
Once again, we are proving our ability to think innovatively by making renewable energy simple, accessible and mobile.

Read more about the launch at the V&A Waterfront here.

Waverley Girls’ School New IT Lab

A partnership between Sci-Bono and Dell has provided the Johannesburg based school with a refurbished 20ft shipping container that will now be used as an IT lab.
The container lab is kitted with desks and computer equipment for an educator and ten students.
Grey Green provided the PV system that will cater to the energy needs of the IT lab, and will allow it to run completely off-grid.

Sci-Bono & DELL Solar Computer Labs

Grey Green has completed a further 3 x 2.5kW off-grid solar PV computer labs for SHAWCO in Kensington, Khayelitsha and Manenberg. In addition to this, a further 4 x off-grid solar powered computer labs have been built, installed and commissioned in public schools around Soweto to be managed and run by Sci-Bono. The PV Panels used for these projects were sponsored by SUNPOWER. The gallery above shows 3D renderings from AutoCAD while actual pictures after installation are shown in the gallery below.

Come Wine with Grey Green

Grey Green have audited six wineries in the Western Cape during the harvest period over the past few months with another two winery energy audits in progress and a further three in the pipeline.

On average, the energy saving opportunities identified at each site could potentially save the wineries approximately R 370 000 per annum with a promising average pay-back period of 3 years. We also calculated an average of 400 tonnes of equivalent carbon dioxide emissions saved through our recommendations.

Highlights of the proposed interventions included: 

  • Effluent Treatment Optimizations
  • Feasibility Studies for Solar PV
  • Waste-Heat Recovery System design
  • Energy Efficient Extraction System design
  • Efficient Lighting Retro-fit proposals
  • Chiller System Optimizations including. insulation

Interestingly, chillers (cooling/refrigeration) accounted for approximately 40% of the total energy consumption, with the exception of those wineries with a distillery. The distillery accounted for 18% electrically and when converting the boiler fuel into equivalent kWh (using the calorific value of the fuel), the fuel accounted for 94% of the total energy consumption!

Lauren almost overshadowed by grape skins
Lauren almost overshadowed by grape skins