Sunday, December 7, 2014

Renewables Changing the Electrical Grid

One of the possibilities I see in Hubevents and Hubeventsnotes is that more people than just me would go to public lectures and share their notes.  My friend Ambrose Spencer has made that possibility a reality with this report on the way the electrical is changing under the onslaught of renewables.
"From a letter to a policy analyst at the state level. 
"Last month BASEA ( highlighted community solar with speakers from Harvard, from Next Step and from the new net metering task force the Net metering and Solar task force.  
"Yesterday I went to hear Francesco Starace, CEO and general manager, Enel Group.  
ENEL is one of the largest owners of electricity system infrastructure in the world.   
Meeting Tomorrow’s Energy Challenges: Why Technology will Define our Energy Future (Mr. Francesco Starace)He said that Italy has gone a long way to the smart grid. 
For 10 years Italy has had smart meters. 
They have been building their smart grid for more than 10 years.
And now they have real time pricing for all commercial and residential customers.
And such a blessing.  People are actually cutting back when the price of electricity is high. 
Another thing he showed is that, in the summer when the sun is shining, the solar installed, about 15 percent of the connected generation, 
has been able to bring down the daytime peak for conventional generation to within just several percentage points of what it is is at 1 am in the middle of the night.. 
I should add that the real time pricing plays a large part of this.  
"But the reason I write is this.   
First, it will be very important for the work of the task force when they begin to consider the alternatives to net metering, especially virtual net metering for community solar, in an effort to rationalize the pricing of the primary and ancillary services provided by the transmission grid and by the distribution grid, that the task force be sure to consider the options in the context of real time pricing for all customers.   
"A few months ago I wrote about distributed generation in the northern part of Jutland in Denmark, where a district heating plant of several Megawatts, is providing ancillary services that include balancing on pricing signals, and also grid stability, specifically voltage and frequency control.  Denmark knows that their future, which includes a lot of distributed generation, both district heating CHP and micro CHP, and they know wind will be able to carry the whole load at times and the district heating assets will be able to carry almost all of the electrical load when the renewables are unavailable.  And so logically they know that they will need to balance the grid and control it with wind or CHP and other distributed resources; large plants will be in decline as a share of the resources until there is not a large enough resource in the large plants to do the grid stability in the conventional manner.   
Batteries have been seen as the future for incorporating larger and larger fractions of fluctuating renewables into the grid.   
"Simulation modeling for engineering design and for economic feasibility in Denmark and in Germany show that this not true beyond a day or two, or the weekend at the very most.   
"Wind lulls there are as long as 5 days and sometimes 12 days.   
"ENEL sees that a much more valuable service, in the beginning, will be for batteries to play a major role in balancing services and in voltage and frequency control.
"If ENEL is correct about this, in Denmark they will not have to install voltage and frequency control and automatic dispatch into as much of their distributed generation;   some of this can be done manually or conventionally by treating aggregates of resources the way large sources provide for stability today; and letting batteries do a lot of the work.   
"Denmark may choose to continue on their path and Italy on theirs.  
"Another benefit from using batteries is that it reduces the amount of needed spinning reserve.  
"And further this use of batteries will make microgrid and cellular grid and other islanding options much easier. Back up generation does not respond instantly.  Electronic controls for governing the flow of current into and out of a battery can happen instantaneously and with great precision.   
"Even if the present government in Washington does not choose to take up a worthy future for our posterity, the rest of the world is providing some of the lessons that will be needed.  
"Starace from ENEL said that much of the grid will need to become bidirectional.  In a question afterwards, I gave the situation of a valley and uplands.  the population and the district heating are mostly in the valley and the wind mostly in the uplands,   Clearly some of the grid will need to be bidirectional.   
"Francesco Starace spoke at the Shorenstein center of the JFK School at Harvard.  It was sponsored jointly by The Harvard Environmental Economics Program with the Consortium for Energy Policy Research at Harvard University
"The meetings of the Electricity Restructuring Roundtable in Boston are archived;  The archives are for speakers who have given presentations in the past.  Some of them have spoken on one of these subjects. I have written to a couple of engineers who have been involved in development of distributed generation resources; and I to stay in touch with these subjects and the decision that  are being made."
Ambrose R Spencer.