T&Ts Solar Power Potential

The Caribbean is universally known for its warm weather, beautiful beaches, rain-forested hills, amazing mix of culture and of course, carnival. Trinidad and Tobago is true to the definition of what the Caribbean represents. Trinidad is the bigger and busier of the twin island republic with its economy heavily dependent on the oil and gas industry. Trinidad is where the true culture of the islands exist with a variety of different races and religions all coexisting in harmony. It is also the home of the biggest carnival in the Caribbean known as “The Greatest Show on Earth”. Tobago on the other hand has the beautiful beaches, rainforest and tourist oriented culture, which is much different from the industrialized sister island, Trinidad.

In this part of the world there are only two seasons, the dry season and the rainy season. The dry season starts in December and finishes in May, with the rainy season starting in June and ending in November. Since Trinidad and Tobago has a tropical climate, there is relatively high temperatures during the day as it is usually sunny, having an average daily temperature of 27˚ C. In T&T, the month with the most sunshine is March and June is the month with the least sunshine. While it can be said that T&T has approximately 12 hours of sunshine per day, this cannot be used as the total amount of sunshine that the islands receive. There are daylight hours and sunshine hours.  Sunshine hours is a climatological indicator, measuring the duration of sunshine in a given period, usually, a day or a year, for a given location on Earth. Daylight hours, however, is usually more than sunshine hours as it does not take into account cloud cover and the diffused light during sunrise and sunset. Now it can be said that Trinidad and Tobago has an average of 12 daylight hours rather than 12 sunshine hours per day. From this 12 daylight hours, 59.5% or 7 hours and 8 minutes is actual sunshine reaching the Earth’s surface and 40.5% of it is when there is cloud cover, haze or low intensity. This indicates that there is an average of 2608 hours of sunlight per year in Trinidad and Tobago.

Graph of total sun hours recorded per month for 2016

In order to fully understand the solar power potential of the country then we must also know the actual size of the country. The combined total area of Trinidad and Tobago is 5128 square kilometres with Trinidad, the bigger of the two islands having an area of 4768 square kilometres and Tobago just 300 square kilometres. The amount of energy that reaches the Earth’s atmosphere is 1370 Watts per square metre, this is for the upper atmosphere but as the sunlight travels down to the Earth’s surface there is a 30% decrease in its power, bringing it to about 1000 Watts per square metre. This means that when the sky is totally clear and sun is directly overhead, peak sun hours, there is approximately of 1000 Watts of solar power reaching each square metre of Trinidad and Tobago. This calculates to be a maximum of 5.13 GW of power reaching Trinidad and Tobago’s land mass when the sun is directly overhead. However, this significantly decreases as the angle of the sun changes throughout the day.

Introducing solar (PV) panels, as previously explained in Solar Power Day and Night, uses the photons in sunlight to generate a flow of charge known as electricity. 

Solar (PV) panels

The most efficient solar panels commercially available have an efficiency of about 22.5%, which are sold at a high cost whereas more affordable solar panels have efficiencies between 14% and 16%. If the most efficient solar panel (22.5% efficiency) converts the total power that reaches Trinidad and Tobago when the sun is directly overhead, it will be able generate 1.15 GW of power. This would be plausible if we assumed that the entire country is covered by solar panels and there is zero cloud cover over the period when the sun is directly overhead. However, this is not possible to maintain as the Earth constantly rotates as well as the entire country cannot be covered with solar panels but this therefore gives an idea of the total power that actually reaches T&T from the sun and the technology that is available to convert this power into electricity that can be used.

National flag of Trinidad and Tobago

Realistically, there is much less than 1000 Watts per square metre reaching the islands over the course of a day and solar panels that are 22.5% efficient are very expensive. Despite this, solar panels of lesser efficiencies that cover rooftops and open areas of available land can still produce a significant amount of electricity for Trinidad and Tobago to drastically decrease the amount of natural gas being used for electricity generation but only if citizens and the government are willing to invest.