The media often touts the raw cost of solar panels, not the total installed costs.
This is a USA link, but the principles apply here, It estimates hardware costs to be only 32% of total installation cost and solar panels less than half of the hardware costs. So even if the modules were free, the total cost of a solar installation may not be dramatically cheaper.
http://sunmetrix.com/solar-panel-installation-cost/
Perhaps more relevant is large scale wind power, which involves bloody big machines. The cost of wind power (which includes manufacturing and deployment) has reduced by two thirds since 2009 and is predicted by some to fall by another 50% by 2030.
http://www.aweablog.org/wind-power-costs-50-percent-reduction-possible-2030/
Wave power has the advantage of producing power at night as well as day, and probably being more reliably predictable than wind. No question wave power in the near future will cost many times that of current large scale wind and solar, however there's no reason that as technology and design evolve, wave power will not undergo a similar cost reduction curve to wind. All it should need is comparable amounts of financial support and incentives to that provided to wind power over the last couple of decades.