Jamaica in 2050 – Part 3: Energy and the built environment
This is the third in a series of eight articles looking at the ways that the world will change between now and 2050 and analysing the implications for Jamaica’s future.
THE WORLD’S buildings require huge amounts of energy to construct and operate. Combined, building construction and operation represent 25 per cent of the world’s total power demand. Construction contributes about 11 per cent of the world’s carbon emissions while operational losses from inefficient buildings contribute about 28 per cent. So any significant improvements in efficiency in construction and operation would substantially reduce both the global demand for energy and the world’s carbon emissions.
Almost all construction in the Caribbean today is based on cement and steel, and each of these industries contributes about 8% of total world carbon emissions. Combined, these two industries are second only to the fossil fuel industry as the world’s largest source of carbon emissions.
It is, therefore, important to develop new construction materials and new building forms that will have lower levels of embodied carbon and also give lower carbon emissions in operation. There is a range of candidates, including cross-laminated timber, which can have the structural strength of steel, resists warping, allows buildings to be rapidly assembled from prefabricated sections, and gives sufficient flexibility to allow the building to withstand an earthquake or hurricane; bamboo strand lumber, plywood or laminates, which have high density and tensile strength and are water and weather-resistant; and eco-composites, natural fibres in a biological matrix derived from plant starches or tree resins.
The use of engineered timber, bamboo, and eco-composites would offer completely new prospects for local agriculture. There is an immense potential market for such industrial crops, many of which grow prolifically in subtropical regions and could be competitively processed and manufactured in Jamaica. This would allow local farmers and processors to become suppliers of building materials for the world.
HIGH ENVIRONMENTAL IMPACT
Another reason why the construction industry currently has such a high environmental impact is that the industry involves demolition as well as construction, with a large part of the material from demolitions going to dumps and serving no further purpose, which means that most of the high-energy-cost materials are effectively single-use. However, there are now prototypes of buildings that are made entirely from natural materials and fully demountable, which means that every component can be disassembled and then reassembled into a new configuration. In future, many buildings could be leased, rather than owned; tenants would move out when their needs changed, and the building would be reconfigured for the next tenant. The current planning framework for London, for example, specifies that all new applications for planning permission must include a Circular Economy Statement that explains how the building components can be disassembled and reused.
With regard to building operation, levels of energy efficiency in most buildings in Jamaica are very low. They have high thermal mass, few are designed to minimize unwanted heat gain or utilise passive cooling solutions. This means that they require cooling in order to remain at a tolerable internal temperature. However, this means that the building sector has considerable potential to become far more efficient in terms of resource use, less environmentally intensive, and less costly.
Net Zero/Energy-Plus buildings represent the most advanced solution to date; highly efficient buildings that generate at least as much power as they consume. Net Zero buildings are designed to maximise energy efficiency, using orientation and insulation to minimise unwanted heat gain or heat loss, maximising the use of sunlight for lighting, natural ventilation for cooling, and using energy-efficient appliances to reduce the need for air conditioning. Energy-Plus buildings generate more power than they can use, so the owners can sell it to the grid. Instead of paying your light bill every month, you get a cheque every month, so your house is working for you. This model has been working since 2008 in Freiburg, Germany, where apartment complexes earn money for their owners by exporting power. If this approach was widely adopted, many of the world’s power stations would become redundant, and electricity grids would no longer be one-way transport systems, but dynamic markets in which customers were also suppliers, buying and selling power to each other. Energy-Plus buildings could eventually make cities net exporters of power.
In 2020, the Institute of Sustainable Development at The University of the West Indies Mona Campus completed the first net zero/energy-plus energy building (NZEB) in the Caribbean. The building is larger than the average house. It contains seminar rooms, offices, and laboratories but generates more power than it uses.
COMPETITIVE ALTERNATIVE SOURCES OF POWER
This approach is becoming even more attractive as alternative sources of power become increasingly competitive. It is now about 50% cheaper to generate electricity from renewables compared with fossil fuel plants, partly because fossil fuels are no longer competitive when environmental costs and subsidies are included, and partly because about two-thirds of the energy from fossil fuels is wasted, lost in mining, drilling, burning, converting, transmitting, using and waste disposal. Renewables involve no extraction, no combustion, fewer conversions, and so have much lower losses.
With sufficient policy push, renewables could be the largest source of power by 2050, mostly from hydropower, wind, and solar. Solar is growing particularly rapidly. Solar-produced electricity has fallen dramatically in price. It is already 20-50 per cent cheaper than in 2019, which means that it is now the ‘cheapest electricity in history’.
The development of perovskite solar cells, which promise to be both cheaper and more efficient than silicon, will bring substantial further cost reductions.
Changes in government policies could significantly shorten the transition. The most important change would be removing the global subsidies for fossil fuels, currently over US$300 billion/year. In Jamaica, the capital cost of solar cells is still a deterrent, so the Government could accelerate the transition to renewables by zero-rating the import of modern solar cells.
Improving energy efficiency in building construction and operation would reduce energy imports, minimise exposure to energy price volatility, increase levels of disposable income, improve the balance of payments, enhance competitiveness, increase the number of investment opportunities, raise levels of disposable income, reduce the national contribution to climate change and support sustained economic growth. Reform of the built environment would, therefore, have substantial long-term benefits for Jamaica.