Opportunities for Locally Generated Power and a Smart Grid

by Michael W. Finkbeiner, Earth Image Dot Net, Greenwich, CT  April 16, 2010

Today there are many options in electric power.  The sale, transportation and delivery of power has been opened for consumer choice, much as telephone service was, following the break-up of AT&T.  First came the baby bells, then the MCI's, and today Vonage and Skype with voice-over-internet technology.  Prices have fallen from as much as 65 cents per minute to virtually free.  So the competition has been a good thing for the consumer.   Nevertheless, when you pick up the receiver, that is, if you still have a land line, you need a local service provider.  And that's true, even if your have an internet service like cablevision.


When it comes to power, we have only one local choice - the power grid and our connection to it though the local electric company.  

In Connecticut this is CL&P or UI, both with a reference to light or illumination in their name.  They own the poles and wires, and in Greenwich a bank of 20-megawatt generators by the Cos Cob Railroad Station.



The State now provides opportunity for CL&P customers to buy their generated power in open market contracts.      

If you had the inclination and know-how, you could sit at your computer terminal, and trade power contracts just like a commodity player might buy-or-sell soy beans.

But there is no need to go to that trouble.  Various energy brokers will call you up and offer you incentives to buy their contracts, which run a penny or so under the CL&P "generation" rate of about 11 cents per KWH.

If you accept, they force CL&P to buy the power from the national grid using your account.  

Is there a downside to this saving of a penny or so per kilo-watt hour?

One aspect of the transaction is you've just let CL&P off the hook for the need to generate and provide cheap, reliable local power.  This might seem harmless, but just because cheap hydro-power is available in New York, Canada or the rest of New England, and even cheaper out west with bigger dams and longer rivers, doesn't mean we should stop working on the problem here.

We have tremendous power resources right here: 

 Look down between your feet. 

 If you pushed a pipe into the ground, the water below would start at about 54 degrees F, and for every 100 ft you pushed lower, the temperature would rise another 2 degrees.  Need a continuous stream of cooling water on a hot summer day?  You're standing on it.  Need to circulate hot water through your radiators on a cold day?  You're standing on it.


Aside from geo-thermal installations going into homes in our area now, there are other tremendous energy sources.

Long Island Sound has an eight foot twice-daily rise and fall of tide.  Each cubic foot of water weighs over 62 pounds and is attracted to the moon's gravity.  It will literally bulge up to get nearer to it, driving the tidal cycle.

This force of water is so weighty that the geologic tectonic plate on which Greenwich sits actually rocks up and down in rhythm with the tides.

Or if you prefer not to see it at all, there's the undersea approach:  
“Each one megawatt unit has a turbine diameter of 11.5m and a fully ballasted weight in excess of 2500 tons. Rotech tidal turbines can be easily grouped to suit tidal streams in locations worldwide.”


One way to utilize this source of power would be to submerge rotary turbines, deep enough so that ship traffic would safely pass over them.  The entrance to Greenwich Harbor transitions from 40 feet to 20 feet of depth, providing an ideal site.  Some of the deepest water in our zone of Long Island Sound is just off Greenwich Point, at nearly 100 feet of depth.  These 1 Megawatt tide generators can be set in arrays.






Another would be to reactivate the tide mill sites already common in our region, such as are found in Stamford at Cove Park or Rye at Kirby Pond.



Stamford's Cove Park is an old mill.


So is the Kirby grist mill in Rye


Cos Cos has its own solution to greenwich Local Power:   Presenting the Green Witch Tidal Power Plan:

Mianus Pond was built by the Railroad as a pond to serve the power plant.  Its dam is set at 15 ft above the old mean sea level.  The base of the dam is nearly dry at low tide.


Imagine this built behind the Mianus dam, submerged from view, operating silently with no energy input except the running water.

The maximum power of the hydro system can be roughly estimated as:

Head X Flow X 5 = kW

The head is in metres and the flow in metres-cubed per second.

Example 1

A River which is as large as the photo shown in Category 5 above.

Estimate the average flow rate to be 4 m3/s.

The head at the site is 2 metres. Therefore the estimated power output would be:

Power (in kW) = Head X Flow X 5 = 2 (metres) x 10 (m3/s) x 5 = 100 kW