Hawaii has an ambitious climate plan, especially compared to the rest of the United States. The archipelago wants to be completely climate neutral by 2045. To achieve this, it is already saying goodbye to the most polluting source of electricity: coal-fired power stations. The first 'megapacks' from battery and car maker Tesla arrived this week. The entire system should be operational by 2022, by which time it will be the largest battery park in the world. The batteries can then together store and supply 565 megawatt hours of power. Hawaii consumes 9.6 million megawatt hours annually. In the evening no sun shines The battery must regulate the supply of power for the environment. After all, the sun does not shine in the evening and the electricity demand - for lighting or electric cooking - is highest. Tesla's megapacks can store up to three megawatt hours each, and nearly 160 are coming to Hawaii. Replacing power plants with solar panels and batteries is uncommon. That has a few reasons; Firstly, batteries are much more expensive than fossil fuels. In addition, batteries cannot hold a charge for extended periods of time. It is a good solution for the day-night rhythm, but for seasonal storage you need other things, such as hydrogen. Expensive electricity, lots of sun However, Hawaii has these problems much less. The sun shines harder and all year round. Even in December and January, the state still gets 200 hours of sunshine per month. The Netherlands receives an average of 50 in those months. As a result, no seasonal storage is required. In addition, the energy price is very high in Hawaii. Being an island, the government imports most fuels by ship. This results in extra costs that we have much less with gas in the Netherlands, for example. Although it is certainly a positive development that Hawaii is closing the last coal-fired power station, the state is far from being there. To run entirely on green electricity in 2045, an important hurdle has to be overcome: oil. Like many archipelagos, oil provides the bulk of the electricity, especially via diesel generators. This dependence on oil is responsible for the high energy price, so the government sees all kinds of advantages to the sun (and wind) as a power source. Lower costs and energy independence are important additional reasons, in addition to the climate, to become sustainable.