Offshore Wind — Why drilling for offshore oil is dumb

Photo of Block Island wind turbines in heavy seas
Block Island wind turbines in heavy seas. Image: Deepwater Wind

The amount of energy generated by America’s offshore winds last year, exceeded by more than four times the total amount of energy consumed by the nation’s people and industry in the same year.  Only a tiny fraction of that wind resource has been harnessed commercially so far. The following map shows average wind speeds off U.S. coasts at a height of 100 meters and extending to the country’s 200 nautical-mile EEZ (Exclusive Economic Zone). The richest wind areas (fastest wind speeds) are off the N. California and New England coasts.

Map showing U.S. offshore wind speeds
Offshore wind speeds. Image from 2016 NREL study of U.S. offshore wind energy resources

The country’s first offshore wind farm became fully operational December 2016. It lies 3 miles SE of Block Island RI. The electricity it generates is delivered by sub-sea cable, first to a substation on Block Island, then on to the Rhode Island mainland where it connects to the state’s electrical grid. Operated by Deepwater Wind Co., the 30 Megawatt (MW) wind farm consists of 5 wind turbines, each rated at 6 MW. Together, they generate annually about 125 Gigawatt-hours (GWh) of clean energy, enough to serve about 17,000 households. Ørsted, the Danish wind company, acquired Deepwater in 2018 for a reported $510 million.

Offshore wind farms are set to become common features along the NE coast in the coming decade. The Rhode Island wind farm is the pioneer. To see it, take a day trip to Block Island. If you’re driving between NYC and Boston, exit the I-95 at Hwy RI-138 (about 30 miles south of Providence); head east to Kingston. In Kingston turn right at Hwy RI-108 (traffic lights but no sign) and head south to Galilee and the Pt. Judith ferry terminal. Park your car at the ferry terminal (the ferry does carry vehicles). The Ferry departs for New Shoreham, Block Island, four times each day, year round. The trip, port to port, takes 55 minutes (scheduled). Rent a bike in New Shoreham, ride 15 minutes south (or walk the 1.8 miles) to Mohegan Bluffs. The wind farm’s five turbines are located about 3 miles to the SE, clearly visible from the island.

Map showing location of Deepwater Wind farm SE of Block Island RI
Deepwater Wind. Image: Landfall Navigation

Construction of the first large-scale offshore wind project, an 800 MW, 84 unit farm, will likely begin this year. The project is owned by New Bedford MA based Vineyard Wind Co., a 50-50 partnership Between Copenhagen Infrastructure Partners  and Avangrid Renewables. The array of wind turbines will be located about 14 miles south of Martha’s Vineyard MA (see map below). At that distance, the wind turbines will not be visible from land. The project will deliver electricity to Massachusetts for an initial price of 6.5 cents per KW hour, the price to rise by 2.5% year subsequently.

Map showing offshore Vineyard Wind lease area
Vineyard Wind lease area. Image credit: vineyard Wind website

According to the National Renewable Energy Laboratory’s (NREL) 2016 study ‘Offshore Wind Energy Resource Assessment for the United States’, the Gross Resource Potential of the country’s offshore winds (excluding Alaska) is 10,800 GW. Of that amount, 2058 GW is listed as Technical Resource Potential, that is, the amount that could be harnessed today using currently available technology. Areas of the offshore wind zone that are not considered technically available at the present time include: areas where the depth is greater than  1,000 m (3281 ft); areas where the average wind speed is less than 7 m/second; shipping lanes; marine protected areas.

The existing electricity generating capacity of the U.S. is 1072 GW (2017). Of that, about 64% or 646 GW is generated by fossil fuel plants. The electricity from those polluting plants could be replaced three times over by clean electricity generated from Technical Resource offshore wind. The Trump administration is promoting offshore oil/gas exploration. What is the justification for spending billions hunting for fossil energy offshore while clean, cheaper, renewable energy blows past the rigs needed to do the drilling? There isn’t one. As electric cars displace fossil powered cars in the coming years, more clean electricity will be needed, not more petroleum.

Memo:
1 Kilowatt (KW) = 1,000 Watts
1 Megawatt (MW) = 1,000 KW = 1,000,000 Watts
1 Gigawatt (GW) = 1,000 MW = 1,000,000,000 Watts

Rhode Island’s Fox Point Hurricane Barrier. Can it handle a big one?

Photo of Huge ocean wave. Image by Ray Collins
Ocean Wave. Photo by Ray Collins

Rhode Island’s Narragansett Bay sits like an open mouth, ready to swallow any hurricane that makes its way up the East Coast. Usually these northward trending hurricanes lose steam when they reach the colder waters off New England. Usually but not always. The Great New England Hurricane of 1938 arrived over Rhode Island with a forward speed of 50 to 60 mph and wind speeds exceeding 120 mph. It carried with it an ocean swell that filled the bay to overflowing.

Map of Narragansett Bay, Rhode Island
Narragansett Bay, Rhode Island. Openstreetmap.org

According to the National Weather Service (NWS-Boston), “The hurricane produced storm tides of 14 to 18 feet across most of the Connecticut coast, with 18 to 25 foot tides from New London east to Cape Cod. The destructive power of the storm surge was felt throughout the coastal community. Narragansett Bay took the worst hit, where a storm surge of 12 to 15 feet destroyed most coastal homes, marinas and yacht clubs. Downtown Providence, Rhode Island was submerged under a storm tide of nearly 20 feet.”

In 1954, Hurricane Carol produced a storm surge of more than 14 feet in Narragansett Bay. Downtown Providence was once again flooded, this time by 8 to 12 feet of water. All levels of government — local, State, and Federal — agreed that something had to be done to protect the low lying city center. The Fox Point Hurricane Barrier, completed in 1966, was the result.

Aerial photo of Downtown Providence and Providence River
Downtown Providence and the Providence River. The Fox Point Hurricane Barrier is hidden behind the I-195 highway bridge. Image: providenceri.gov

All travellers on the I-195 Highway pass within feet of the Barrier as they drive across the eight-lane bridge over the Providence River. But those who want to look at the barrier and appreciate its design, leave the highway on the east side of the river, and make their way back to Bridge Street and its small riverside park (marked in yellow on the satellite view below)

Satellite view of Fox Point Hurricane Barrier
Satellite view of Fox Point Hurricane Barrier and vicinity. Google Maps Image

The barrier is located a couple of hundred yards up stream from Fox Point, and just north of the I-195 Highway Bridge. It consists of a concrete wall built across the Providence River and earthen dikes that extend flood protection about a thousand feet over the land on each side of the river. Built into the river wall are three, 40 foot wide gates, each weighing  53 tons. Under normal weather conditions, the gates remain open so as not to impede the flow of the river. The gates are located at the eastern end of the river wall. They can be seen in the satellite view above.

Fox Point Hurricane Barrier, Providence, RI
Fox Point Hurricane Barrier’s three flood gates, looking down stream from park on Bridge Street. I-195 Hwy bridge in background. Providence RI. Image: Brown.edu

An essential component of the barrier system is the pumping station consisting of five massive 4500 H.P pumps, each as big as a grain elevator. When the flood gates are closed to keep a storm surge out, the entire flow of the river must be continuously pumped up and over the barrier. Otherwise the river would be held back, overflow its banks, and flood the city. The pumping station is housed in a building at the western end of the river wall (its roof is plainly visible in the satellite view). The five pumps, operating together, can lift 3.1 million gallons per minute and discharge the flow to the downstream side of the barrier.

Fox Point Hurricane Barrier, Providence RI
View of Fox Point Hurricane Barrier from Bridge Street pocket park. Pumping Station at far right. Google Image

The barrier gates have been closed against storms several times since going into service in 1966. During Hurricane Sandy in 2012, the water crested at 9.5 feet. But the barrier has yet to experience a direct hit from a category 4 or 5 hurricane. As coastal flooding increases in the coming years, hurricane barriers of all kinds are going to be in the news.