To what extent is the development of the renewable energy sector coupled to the oil & gas price trend?

As I've noticed in some european countries, governmental as well as private sector spendings in renewable R&D went down; Some long term projects and their allocated budgets where put on hold. State regulations to subsidize the sector for the benefit of the end-user where either reduced or fully canceled. 

Nevertheless this downtrend of investment in renewables (while the oil/gas price is low) is mostly noticed in  the west continent as in the EU and the US States, whereas China's and India's renewable sector, specially solar power is still on the boom, more or less decoupled from the oil/gas trend!

Now if we want to tackle some trends in the renewable/environmental business (beside that of sustainable energy production), we can notice an upward trend in some sectors such as in the electrical car and battery storage production and R&D spendings. Just look at Toyota and Tesla e-cars sales trend and the huge investments by all other car makers to catch-up on this technology.

So can we really generalize and conclude that a down-trend in oil/gas price means lower investments and a down-trend in the renewable sector?

The relationship between the development of the renewable energy sector and the trend of oil % gas prices is a positive one. When the Oil & Gas prices go down, the development in renewable energy sector goes down as the focus now is on utilizing the oil and gas to the utmost extent. But when the prices of oil and gas go up, the development in the renewable energy sector goes up too trying hard to push for alternative sources.