PUCSL & University of Moratuwa to Introduce Self-Powered, Heat Resilient, Low-Cost Housing Model

PUCSL & University of Moratuwa to Introduce Self-Powered, Heat Resilient, Low-Cost Housing Model


The public Utilities Commission of Sri Lanka (PUCSL), the electricity sector regulator, signed a Memorandum of Understanding (MoU) with the University of Moratuwa, early this year, to collaborate and introduce a self- powered housing model for low-income households, with the aim of providing the best architectural housing structure, with the use of maximum daylight.

The MoU will lead the University of Moratuwa and PUCSL to carry out a collaborative research project to identify the energy demand patterns of low-income households, and to establish “End User Energy Demand Indices” with a sample housing model for low-income households in rural, estate and urban areas.

“Energy Conservation is one of the functions that PUCSL is empowered with by the Sri Lanka Electricity Act,” said PUCSL Director corporate communication explaining the initiative.

“Over the past years, we have taken a number of regulatory measures to promote energy conservation to stabilise increasing energy demand in Sri Lanka, and this is one of the key regulatory initiatives such, that we have identified for this year as the country is in need of low cost housing models with the maximum usage of energy.”

An accomplished Chartered Architect, and a Senior Lecturer at Moratuwa Universitys Architecture Department, Dr Indrika Rajapaksha is a researcher specialising in environmentally-sustainable building and urban designs, with international research experience on the impact of human development on the environment. She has presented and published several papers on passive cooling strategies for human thermal comfort within tropical built environments. Dr. Rajapaksha is the principal investigator, who is in charge of the project.

In 2015, parties to the United Nations Framework Convention on Climate Change (UNFCCC) met in Paris and hammered out an agreement, dealing with greenhouse-gas-emissions mitigation, adaptation, and finance. Each country submitted their (Intended) nationally determined contributions (INDCs), which serves as its greenhouse gas emission reduction target.

She explains that Sri Lanka must cut down the greenhouse gas emissions of the energy sector by 4% unconditionally and 16% conditionally, from the 2010 baseline, by 2030. “When looking into the energy sector and the housing stock, the domestic sector demands more energy in the country compared to other sectors. In terms of energy demand, and the reduction strategies, we have not looked into it in a very comprehensive manner, since there aren’t any guidelines or ratings for the accepted standard of energy consumption for a house. Even the other building types are the same, so if we are to approach achieving these reduction targets by 2030, it is timely that we start giving priority to developing energy codes and ratings.”

Cooling Poverty

She points out that, with contemporary conventional housing design, most of the interiors become overheated. “Since we are into an era where global warming is evident, and we cannot stop the temperature increases, so we have to get ready future-proof houses which will not make the interiors heated up.”

When interiors get heated, cooling is needed to make the houses comfortable. However, because of financial restrictions, people in low-income settlements do not prioritise spending in order to cool themselves.
“So when there is not enough money to cool or to bring themselves a thermal comfort requirement, it is called ‘cool poverty’, says Dr. Rajapaksha. “At present, due to the environmental hazards and the heating and the poverty situation, quality of life would not be at the acceptable level.”

These houses often do not have even a window, and little natural light or cooling, which leads to physiological and psychological illnesses. Meanwhile, global warming and population ageing, are synchronised issues for the whole world. In Sri Lanka, by 2030, one in every four citizens will be an elderly. Elderly people are a vulnerable group, whose vulnerability will increase with global warming, especially among the poor.

Holistic Concept

Considering these factors, the University of Moratuwa and the PUCSL held discussions to come up with a holistic solution. They developed a concept for a heat-resilient self-powered houses, in which the interiors do not draw heat from outside, which provide the required comfort level for human beings, and do not demand energy to operate, for artificial light or for air-conditioning.

“This concept was initiated, with the current project which I am working on, on global challenges, funded by the UK Government in collaboration with Coventry University and three Asian countries: Sri Lanka, India and Indonesia, with China as the other collaborative partner.”

The project plans for a minimum cost, for an affordable solution for low-income settlements. Controlling the heat ingress maintains thermal comfort standards and does away with the need for artificial cooling. The planned house will make the occupiers physically comfortable in terms of interior cooling, and psychologically comfortable due to natural lighting and cooling conditions. It will also contribute to satisfying the lives of the elderly and making them healthier, which will be more supportive of future health budgets.

“By doing this project,” she clarifies, “we are going to support seven SDGs [Sustainable Development Goals adopted by all United Nations countries] coming from poverty and inequality; sustainable cities and communities, as well as energy efficiency, health. So, likewise, if we could implement this project … I am sure that we are achieving the required INDCs which the country has pledged.”

Solar Panels

Designs should not allow heat gain in the interior, but heat loss. Most current building designs lack defensive strategies to limit heat ingress; they have more glass transparent surfaces and wrong orientation, and make buildings more perforated or with window facing the wrong direction.

To make the interiors healthier requires cooling them naturally while harnessing natural lighting. “The energy demand was lessened by 70%,” Dr. Rajapaksha says, “if you could control these operational energies, and the balance is to be supported not by connecting to the national grid, but by having the energy generated capacity within the house itself.”

She adds that this means a self-powered house, the energy demand for which will be supplied by efficient solar panels. However, the project faces its own particular problems. For example, since low-income houses have an average area of 500 sq. ft. (50 m2), the roof area available for solar generation – in Sri Lanka the optimal generation occurs with roof-mounted panels – limits the number of solar panels to two or three per house. For a house to be self-powered, the goal of the project, the energy supply from these two or three panels should equal the energy demand of the house.

The Chinese partner, a professor famous among Chinese academics for developing innovative solar panels, is now in the process of developing country-specific panels for the three countries in the project.
She outlines the thinking for the future, which is to “couple this model with the housing ministry and develop an integrated energy and housing policy which could bring forward the healthy, heat-resilient self-powered houses.”

On the other hand, she points out that there is a limit to the number of new buildings that can be erected. The international practice is not construct more and more new buildings, but to make the existing buildings suitable for the current demand.

“We have to revitalise or retro-fit. Retrofitting is very important. That should be the strategy, but we do not have any frameworks to go and do a proper retro-fit in this country.”

Energy Indexes

Another limitation in the framework is that lack of proper data bases of energy patterns in low-income houses. These are essential to initiate solutions, so there can be no possibility for evidence-based solutions.

So, the project includes developing such data bases, says Dr. Rajapaksha. “This project will also show a path, or develop a framework, for how an evidence-based approach should give permanent solutions to any issues coming up in the country, at the local level. For the first step we are going to develop energy-index databases, where we are going to identify the benchmark energy consumption patterns of low-income houses, for which we have selected three main districts: Colombo, Kandy and Moneragala. After developing the data base, we know where we are. So this is a bottom-up approach which is going towards consolidated solutions.”

Most countries, have benchmark standards on which to base building energy codes and energy ratings, which builders must abide by in order to get planning permission. However, Sri Lanka’s building sector has no such standards, and builders can go ahead with building approvals without considering any energy efficiency standards, ratings or measures. The main measure used in the energy sector in regarding to building energy indexes is the number of kilowatt hours of energy spent in one square metre of area for a year (kWh/m2/annum).
She describes the problem: “Now at the moment in the building sector, we have the cost to build a square metre, but we have not gone into evaluating the cost of a square metre to operate for one year, how much of energy you use. It is the time for us to come up with an energy index and the energy rating, dependent on the benchmark value. For the first time, the PUCSL and the University of Moratuwa have decided to establish these benchmark standards for low-income houses, and later to follow up in the housing sector.”

Any house with an energy consumption above this benchmark value would receive energy obsolete status. At present, the majority of the office buildings in Colombo, are energy-obsolete, because they exceed the rating requirement of the energy index.

The next step, after developing an evidence-based data base on energy demand, would be to develop an innovative house for these low-income communities, which will not be connected to the national grid. Thus, it would be self-powered to support the internal demand, meaning that the it would have sufficient solar panels to be energy-self-reliant.

“Energy reduction or energy efficiency is very important,” She summarises,”but we don’t know the levels to which we should go, in terms of energy efficiency. This is, in the whole world, governed by energy codes and energy ratings, has applied different strategies, and why Sri Lanka is not doing this is a question which is in my mind for more than ten years. We have an energy code and we are not in a position to make it mandatory. It is time for us to do this, otherwise achieving INDC targets would not be possible.”

Christine Arumugam – Pillai