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ENERCUBE: Energy-generation combined with Housing for the Developing world [updated 02/06/15]

In this study, we aim to develop a prefabricated housing concept, named ENERCUBE, which combines innovative architecture and energy generation through the integration of solar panels. We want to bring contemporary design – an aspect that is typically ignored - to affordable housing in order to provide an improved living environment for families up to five people. Due to its modular construction, ENERCUBE is low cost and can be assembled fast by unskilled labor. Effectively, our concept innovates along two dimensions: it reinvents the design of housing units for the underprivileged and transforms the business model for affordable housing through solar energy production.

Photo of Vasilis Zoupas
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Central Hypothesis

The central hypothesis of this study is to test if combining innovative architecture with solar energy production into a single housing unit is a bold and scalable solution that can make a meaningful impact on the global issue of affordable housing and energy production. 

Key Findings

We worked together with experts to develop the design and floor plans of ENERCUBE. Our final design integrates a photovoltaic (PV) system in the roof. We propose that the energy generation associated with ENERCUBE is linked to the property ownership and sold back to the grid through purchase agreements with electricity providers in blocks of 200 units. These future cash flows are guaranteed and can be securitized giving people access to capital. In economic terms, these families effectively receive a rent from the grid for making their land available for energy production. This in turn helps them finance a housing unit that substantially raises their living standards. 
Overall, our research shows that the combination of sophisticated design and solar energy production delivers an affordable housing solution that has the potential to dramatically improve living conditions for the poor. 


Selecting a benchmark location for our hypothesis will make the analysis more feasible and comprehensive.  The main two factors driving our choice are: (a) critical housing problems and (b) radiation ratings. We identified South Africa as a location that fulfills the above two criteria.

(a) Poor urban areas in South Africa are referred to as Townships and they suffer from overcrowding and squatter and backyard buildings around urban areas. Given the scale of the housing backlog and the rapid growth in housing needs, there is an incentive for government to spend money in this area and embrace innovative new solutions. The South African government spent R16-billion on building new houses and sustainable human settlements for poor South African in 2010/11, a domestic record only second to that of China.

(b) Radiation ratings are the key driver to identify locations where solar energy production is optimal. South Africa is a prime location for solar energy as it receives over 2,500 hours of sunshine a year; its solar radiation output is more than twice that of Europe, making it one of the highest in the world (24-hour global solar radiation average is 220 W/m2 for South Africa, compared to 150 W/m2 for the USA and about 100 W/m2 for Europe.

We also favor a location that incentivizes investment in solar energy. In recent years, South Africa saw a significant rise in the number of PV installations as well as general interest in the technology. An example of the growing PV interest in South Africa is the million-dollar plant being built by state controlled energy monopoly, Eskom in the Northern Cape.

Other factors we looked at include the stability of the political and economic environment (SA ranks 35 in the “doing business ranking” vs. India at 132), the level of sophistication of the financial system, housing inequalities and backlogs, poverty (46% of the population), a mature energy sector, familiarity with the area and possible networking opportunities through personal connections.



Our intention is the name of our product to reveal its core attributes. As a creative blend of the words energy and cube, the archetypical symbol of spacing unit, we chose ENERCUBE as an intriguing name that accurately reveals the essence of the project.

Maximizing energy production, adapting to the local climate and addressing South African living customs has led our team of design experts to reconsider some aspects of the original plan and section by extending the effective surface of the roof, both for energy harvest and rainwater collection, and by incorporating a semi-private, covered porch to the benefit of every unit, taking into account the time South Africans like to spend outdoors. The size of each module has been fixed to a 3,50 meters width by 8,40 meters length, an effective space of 29,50 m2.

Indoors we insisted on a scheme that maximizes functionality while addressing the issue of flexibility; a unit that is easily reprogrammable and can compensate for future family needs. With the exception of the wet areas of the kitchen and the bathroom, the rest of the interior walls are envisioned as demountable partitions. Storage room is considered critical and is incorporated as an integral part of the design.

Enercube is presented 100% as a long-term housing solution and in fact demands a multi-faceted approach and all of the above parties to collaborate closely. We consider other lightweight designs currently available in the market as extremely more efficient for the purpose of disaster-relief temporary housing. Enercube's strength comparing to other similar initiatives lies in the direct association of the housing design with the energy production process, a design that at the same time does not disregard basic aesthetic and architectural features, strongly opposing the common misconception that low-income housing shouldn't or can't look nice.


Our main concerns regarding the construction method is scalability, ease of production and low cost of transport. The chosen method will have the potential to provide a global solution in diverse geographical areas with growing needs. We identified industrialized, prefabricated modular construction as the optimal building method capable to catch up with the emerging urbanization trends and the housing deficits that they create.

The house is designed in wall, roof and floor panels with a width of 1.20m, ensuring a standardized prefabrication process. Each panel is broken down in four elements - a lightweight metal substructure , water-resistant plywood panels as the outer layer, Isotherm thermal insulation as a middle layer and low-cost Oriented Strand Board panels as interior finishing. Due to its modularity, each house can be flat-packed, transported in pieces and mounted on site. Medium skilled workers with the support of local labor can assemble each module in the course of a day or two. The maintenance of each unit and of the communal spaces will be a joined responsibility of the home-owners and the utility company.

Energy generation will be coupled with efficiency in energy consumption. The installation of Solar Water Heaters combined with Energy Efficient Lighting will contribute to the overall performance of each unit. The benefits of such technologies were made obvious in the recent Kuyasa low-cost urban housing energy upgrade project in Khayelitsha, near Cape Town.


The laying out of the emerging urban plan becomes of primary importance to the Enercube Project. The Enercube is less about the single unit than it is about the composition of these units into a meaningful aggregation that achieves urban qualities - it is less about the single user or family than it is about the community as a whole. In the same way that a community is more than the sum of its individual members, the urban plan of the Enercube project will be more than the sum of its individual modules.

We approach the problem of urban form through criteria of density and scale, while addressing questions of program, circulation and aesthetics. The design will be customized on a project by project basis, given the plot characteristics, size, morphology and orientation, as well as the ethnic and tribal characteristics of the population group for which the project is intended. The plan is estimated to be broken down in neighborhoods of approximately 0.25 Hectares in size, housing 20 Enercube modules in average. This figure is translated to a population density index of around 28.000 inhabitants per square Kilometer (estimated 3.5 per household as an average). A critical balance needs to be established between social well-being (personal safety, health and wellness, shelter, sanitation, equity, personal freedom and choice) and energy production. Special purpose buildings (schools, medical centers, nurseries, etc.) will be erected in designated areas of the plan. These buildings could follow the general guidelines of Enercube, but do not necessarily need to follow the module architecture.


Expanding access to finance can play a very important role in reducing poverty among underserved communities. Among other things, access to finance can facilitate income-generating opportunities. The poor can also take advantage to build capital and improve their living conditions, especially when they are homeowners themselves. So how do we provide people with sustained income and secure tenure based on their own merits while creating a viable investment proposition for commercial investors?

The answer is scale. As already mentioned the energy production associated with each housing unit is linked to the property ownership and will be sold back to the grid through purchase agreements with utilities. These future cash flows are guaranteed and can be securitized in the form of a mortgage. In the case of South Africa, Eskom, the dominant, government-owned utility company, tenders for solar projects based on a minimum capacity of 1.00 MW. Provided that according to our calculations, a single unit produces 5,160 KWh/year and the feed-in tariffs are 2.5 ZAR/KWh, purchase agreements need to be bundled in minimum blocks of 200 units!

Based on an investment horizon of 20 years, we estimate that a cash flow of $1,677 per year can be generated per unit. The overall unit cost, including PV equipment, transportation and installation amounts to $11,700 resulting in an NPV of $1,122.75 per ENERCUBE. This provides a good basis to attract private investors but we argue that government and the country’s utility provider will have a key role to play to make that happen.


What community does this idea benefit and who are the main players?

1.6 Billion people around the world live in inadequate housing conditions and as a result struggle with illness, insufficient education and crime. Despite the positive impact of micro-finance, the number of people in substandard housing is increasing because of demographics trends such as continued urbanization and growing wealth disparity. If these trends are not managed, the United Nations projects the number will grow to 3 billion - 40 percent of the total population - by 2030. In order to make a meaningful impact on the global issue of inadequate housing, new and disruptive business concepts are needed. [update 02/06/2015] Our target group is underprivileged communities whose members suffer from unemployment, lack of education, poverty, homelessness, discrimination etc. Communities that above all are in need of a holistic support, a new vision for their future not reduced to the form of financial aid. The Enercube addresses its community needs in a direct way providing proper housing and proper sanitation - and in a more indirect way forging the path to this new shared vision. The end-user experience will be a feeling of comfort and safety - a safe haven for children to grow and be able to play and do their homework. STAKEHOLDERS The Government needs to allocate land for the project and issue individual "leases" for at least 200 plots. The future residents will be subsidized partially by government funds but will also be burdened with a mortgage issued by private investors at a South African Bank with an interest rate plus adequate risk spreads. The residents will only be able to gradually pay off the mortgage when a steady agreement has been reached with the utility company, in our case probably ESKOM, for a 20 year purchase agreement on a fixed rate (inflation included).

How does your idea specifically help your community rapidly transition to renewables?

[update 02/06/2015] By combining energy generation and housing, we can essentially tackle 2 main problems at once and force increased adoption of solar panels. The Enercube proposition is aiming towards a new vision - a community that embraces its future in connection to renewable energy - a solar community that could foster to its members a whole-life approach to sustainability.

What early, lightweight experiment can you try out in your own community to find out if the idea will meet your expectations?

It is quite impossible to test this product in the context of a developed country. Therefore, we selected South Africa as the benchmark location to test the commercial viability of our business model (severe housing issues & high solar radiation) [update 02/06/2015] Our research so far has been of academic nature, gathering information on geography, culture, typical household structure, demographics, education, health, employment and unemployment, access to basic services, crime, migration patterns etc. We have also studied surveys on existing types of housing, on models of financing and of course the literature around affordable housing design as a whole and for South Africa in particular. Conducting on-site research by contacting some potential end-users is very hard at this point purely because of physical distance. We acknowledge the need to engage directly with the community to allow the project to take a more specific form and are willing to do so in the near future.

What skills, input or guidance are you keen to connect with from the OpenIDEO community to help you build out or refine your idea further?

[update 02/06/2015] The input we are extracting from the Renewable Energy Challenge has already been invaluable for the Enercube Project. The transition to Renewable Energy can only come through the collaboration of many; governments, the private sector, communities and individuals. The OpenIDEO community offers the mold where such collaboration can take shape. We are keen to see the extents to which already among the 20 groups selected for the Refinement Phase ( but also with many more that did not make it to that phase) a strong coalition of ideas and forces could be established. With Benjamin Kimmich and Avava Systems to strengthen the design of our prototype, with Eden Full and Jake Schual-Berke to make our PV systems more efficient through the course of the day, with Simon Heereman and Natalie Lake to help us incorporate ingenious low-cost waste-management systems in our prototype, with Ramiro Sanchez Caballero and the "PowerGym" team to imagine small technological breakthroughs that could revolutionize the user-experience, with the "Energy Pop-Up" team and Nathan Lucy's team to guide us on how to best approach communities, with Malachi to think how we can go beyond the house itself and help community members build a new identity, with Tosh Szatow, Anna Schneider and Gavin McCormick to expand our funding possibilities and broaden our understanding of how ideas can come to life. To name only a few!

Please indicate which type of energy is most relevant to this post:

  • Solar

This idea emerged from:

  • A Student Collaboration


Join the conversation:

Photo of Natalie Lake

Hi Vasilis,

I ran across this video on National Geographic and I thought it might interest and inspire you !

Photo of Natalie Lake

Hi Vasilis,

Sorry to be back so soon but I thought you might be interested in connecting with Benjamin and his team at Avava. They are trying to build sustainable affordable homes as well and it reminded me of your idea.

Hope you find this useful!

Photo of Benjamin Kimmich

Hey Natalie, thanks for introduction!

Vasilis, I think you and I share very similar goals for combining renewable energy and innovative architecture. Avava Systems has a been working on afforadable housing for a number of years and we developed a few successful prototypes and even tested them in the desert.

Our units are shipped and stored flat-packed and can be assembled in only a few hours. This makes them especially good for disaster relief as well as affordable housing. Regardless of which ideas are chosen for this challenge, we would welcome the opportunity to collaborate with you! Please feel free to contact me at

Good luck!

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