Cost Of Energy


The economic success of SurfPower depends on its ability to deliver electrical energy at a competitive cost. SurfPower can gauge its competitiveness by comparing its energy yield versus installed cost with that of wind turbines. The ratio of the annual energy yield in kWhr, divided by the capital cost for on-shore wind turbines is typically, about 1.75 and 1.2 for off-shore turbines.

Seawood Designs has estimated SurfPower performance for a 50 buoyant wing system using real time sea surface data for a calendar year on a site with an annual energy flux of 27 kW/m. On this site the system will deliver 25,000,000 kWhr to the grid annually. This implies the installed capital cost must be equal to or less than $14.3 million to compete with on-shore wind energy or $20.8 million for off-shore wind. Preliminary system component designs have been prepared and issued to suppliers for pricing. In the absence of vendor quotations at this time, Seawood Designs believes the following component design cost targets are achievable.

Using the currently available "component design cost targets", the total system cost is $25.9 million for the 50 wing 15 MW plant. This gives an energy yield/cost ratio of 0.96 that is not competitive with wind when operating on the afore mentioned site (off the west coast of Vancouver Island). More energetic sites are available. A similar 32 kW/m site may well deliver 30,000,000 kWhr annually that raises the energy/cost ratio to 1.16. – very much in line with off-shore wind. The wave regime that the foregoing energy recoveries are based is somewhat unique in that 75% of the annual energy is delivered in the six winter months (a good match with typical seasonal demand curves). This bias however, toward the winter months, suggests significant amounts of energy are wasted because the energy in extreme winter storms cannot be recovered whereas a more balanced wave regime may deliver considerably more energy.

Obviously, SurfPower will only be able to compete with on-shore wind turbines if capital costs are reduced and/or more optimum sites are found. Seawood Designs continues to address both issues. In regard to site selection, Surfpower was designed to take advantage of shoaling near the surf zone that causes the wave height to increase. This effect  is very beneficial to SurfPower and may well boost energy yield very significantly. Other naturally occurring geographical features can also be taken advantage of to improve performance. Seawood Designs will be investigating these opportunities as we move forward as well as find ways to minimize capital cost. Not surprisingly, wave energy site prospecting is little different from that required for wind energy.

SurfPower does offer economic advantages in regard to driving reverse osmosis desalination plants not available from wind and other renewable energy concepts.

Component Design Cost Targets

Buoyant Wings

Fabricated from aluminum. The estimated weight is 16,000 kg. Using a fabricated cost allowance of $8/kg, suggests a design cost target of $128,000.
50 Wings - $6.4 million.

Seawater Pump

Seawood Designs has developed a long stroke piston pump design that will have a long service life in the corrosive and abrasive environment. The design cost objective for the pump is $150,000 that includes the flexible connections required at the pontoon and pump piston rod connections.
50 Pumps - $7.5 million

Seabed Anchors

A number of choices are available depending on site conditions (gravity rock-filled base, rock anchors, and suction caissons). An allowance of $100,000 per anchor installed is suggested. This includes pre and post lay surveys and geotechnical reports.
50 Anchors - $5 million

Collection Main

Approximately two kilometers of main are required for a 50 pontoon system. A preliminary estimate indicates the cost to be $3 million.

Collection Main - $3 million

Pelton Turbine/Generator Station

Vendor estimates suggest $3 million be budgeted for the generating plant.

Pelton Turbine/Generator - $3 million

System Assembly and Start-Up

Pontoon Installation and Start-Up: Est. - $1 million