It has been nearly two months since Hurricane Maria, a category 4 hurricane, devastated the electrical grid of the Caribbean island of Puerto Rico. Over 80% of the island is left without power. The coal and oil plants in the south-east of the island suffered some of the worst damage from the storm. The island is beginning a long re-building process on not only these, but the already-dilapidated power lines. Citizens are currently reliant on back-up diesel-powered generators, but schools remain shut, businesses are closed, and tens of thousands are fleeing the island.
The Puerto Rico Electric Power Authority (PREPA) – with complete responsibility and monopoly over the generation, transportation, and distribution of electric power on the island – was forced to declare bankruptcy earlier this year, after operating on a deficit of around $354 million, attributing around 58% of its expenditure to the purchase of fuel – predominantly oil. Despite tens of millions of dollars being spent by governments on projects planning to reduce the island’s dependency on oil by the implementation of solar and natural gas projects, nothing has happened, and the island can attribute only 3% of its energy to renewables.
While relief staff struggles to restore the outdated, tumble-down grid, the opportunity to revolutionise Puerto Rico’s energy sector has captured the attention of politicians and environmentalists alike, including Tesla founder Elon Musk. Musk has been in discussions with the Puerto Rican Governor regarding his solar-powered ‘microgrid’ technology, which has been successfully implemented on some American Samoan islands already. Put simply, the microgrids operate by capturing solar energy in panels, then storing and converting the energy into electricity via ‘powerpacks’. The systems can operate independently of the main power grid, making them less vulnerable to widespread power outages.
Microgrid in Ta’u, American Samoa
In November 2016, a subsidiary of Tesla completed an $8 million installation of a microgrid on the island of Ta’u, American Samoa. The microgrid, comprised of 5328 solar panels and 60 powerpacks on seven acres of land, saw the island transition from 100% diesel-fuelled power to completely solar-powered. Capable of providing 1.41 MW of electricity, it can apparently recharge to full capacity within seven hours, and can provide power to the island’s 600 inhabitants for three days with no sunlight.
The installation of the microgrid will offset the consumption of around 110 000 gallons of oil a year, not taking into account the fossil fuels involved in the production and transportation. While this transition to renewable energy is highly advantageous in terms of greenhouse gas emission and fossil fuel consumption, the problem with solar energy is that it is inherently intermittent and unpredictable, and while it is a feasible to power the island’s small population, is it truly feasible in the much larger, more densely populated island of Puerto Rico? How true is Musk’s claim that there is no ‘scalability limit’ for the technology?
Are Solar-Powered Microgrids the Future of Green Energy Production?
The island of Ta’u is a fantastic example of a successful transition to renewable energy, severely reducing the use of fossil fuels and preventing the production of 1100 tonnes of carbon dioxide emissions per year. While this technology is ideal for the sparsely populated island of Ta’u, the power consumption per capita and the much larger population of Puerto Rico pose a challenge to the microgrid technology. Based on a power consumption of 606 W per person and a population of 3.41 million, Puerto Rico’s power consumption equates to around 2.07 GW, approximately 1500 times the consumption of the small island of Ta’u.
This is not to say that Puerto Rico does not have an ideal climate for the utilisation of solar power, with a UV index of around 7 in the winter and exceeding 10 throughout summer. Comparatively, the UK rarely reaches an index of around 7 at the height of summer.
In the wake of storm Maria, Puerto Rico has been presented with an opportunity to pioneer the use of solar energy on a national scale, following in the footsteps of other nations such as Costa Rica who have transitioned to predominantly renewable-based energy. Although there are obvious issues regarding consistency associated with solar-power and the challenges we face in the development of highly efficient solar panels, implementation of microgrids in a network of renewable-based energy production could help Puerto Rico make a transition from almost wholly fossil-powered to a revolutionary renewable energy grid. Microgrids in tandem with renewable energy sources, including solar panels, could potentially shape the future of national power networks and mitigate the effects of extreme-weather damage – preventing communities from suffering without power for months. While the reconstruction of the Puerto Rican power grid faces financial and technical challenges, the project offers a unique opportunity to showcase the benefits the transition to renewable energy could have on a national scale.