EUROPE POWER-Spot mixed, German prices lifted by decline in renewables

* Increased nuclear availability pressures French prices

* Forward curve slides alongside oil

PARIS, Aug 25 (Reuters) - European prompt electricity prices for day-ahead delivery were mixed on Thursday as a fall in wind and solar output lifted German prices, while an increased availability of nuclear power weighed in France.

Although power consumption in Germany is expected to fall by 700 megawatts (MW) on Friday as demand eases ahead of the weekend, a corresponding slide in power supply from solar and wind renewable sources is seen supporting prices.

Combined wind and solar power production will fall by 280 MW day-on-day on Friday according to Thomson Reuters (Dusseldorf: TOC.DU - news) data, and Germany is seen as a net importer of about 3.3 GW of power during the period.

In neighbouring France, electricity demand has remained strong all week due to scorching weather. However, increased availability of electricity from nuclear reactors will blunt demand, keeping pressure on prices.

Nuclear power availability, which accounts for about 75 percent of French electricity, is expected to rise by 1.6 GW day-on-day.

The French government said late on Wednesday it will launch a series of tenders for a combined capacity of 3,000 megawatts (MW) of solar plants as it seeks to boost solar capacity from the current 6.7 GW to 10.2 GW by end 2018, and around 20 GW by 2023.

German baseload power for Friday delivery rose 0.2 euro or 0.69 percent, to 29.20 euros ($32.97) per megawatt hour (MWh), while the equivalent French contract fell 0.35 euro or 0.98 percent, to 35.50 euros/MWh.

Along the forward power curve, prices fell on Thursday with the German year ahead price Cal'17 nearing low levels reached in May as it tracked the fall in oil and other energy prices.

Oil prices slipped on Thursday as the market focused on oversupply and fading hopes of a production freeze.

German baseload power for next year, Cal '17, fell 0.23 percent to 25.79 euros a megawatt-hour (MWh). The equivalent French contract was at 31.45 euros/MWh, 0.2 euro or 0.63 percent down.

European coal prices for 2017 fell $0.25 or 0.44 percent to $56.25 a tonne. Front-year EU carbon allowances rose 0.08 euro or 1.74 percent to 4.69 euros a tonne.

The Czech year-ahead position was untraded at the previous day close of 26.40 euros/MWh, while the day-ahead position rose 0.34 percent to 29.10 euros. ($1 = 0.8856 euros) (Reporting by Bate Felix; editing by Mark Heinrich)