The coal price fell to a record low as a result of record-setting price falls in the energy sector and a surge in wind power prices.
The fall in the price of coal has led to an increase in nuclear power and the wind power sector has seen its share price surge to record levels.
In North America, the price fell almost 70 per cent to $US4.72 per tonne on Tuesday, making it the lowest price for coal since the financial crisis, according to the US Energy Information Administration.
Meanwhile, the cost of solar energy fell to $AU1.20 per kWh from $AU3.55 per kWh.
On Wednesday, the market capitalisation of coal futures fell to over US$US17 billion after falling below US$20 billion on Tuesday.
While coal has been losing ground in recent years, the solar market is still relatively strong.
The value of solar PV panels and inverters, which are a crucial component of the system, has grown by almost $US600 million since March.
The US has the third largest installed solar capacity in the world after China and India.
The US also has a significant solar industry.
In 2016, the US installed more than 4.5 gigawatts of solar power, with more than 6.7 gigawatts in the solar photovoltaic market, according the US Department of Energy.
Wind energy was the next best performer in the sector at US$4.47 per kWh, up nearly 50 per cent from a record high of US$5.14 in March.
Solar energy has been particularly strong in Australia, with its market capitalization of $US5.3 billion up about 10 per cent since March and the biggest rise in the past year.
There are also other solar power projects on the horizon in the US and overseas.
A new project in Texas is due to go online this year.
A wind farm in South Africa is due up next year.