This forum is about wrong numbers in science, politics and the media. It respects good science and good English.
Acting as an enginaster --
I envision a system which announces itself to the grid using the power line itself as the means of communication (as an enginaster, I needn't worry about the vagaries of communication through a transformer). The system informs the grid of the current power available and its relevant characteristics. The grid talks back and tells the micro gen system where to adjust itself based on the current load demand etc to allow seemless connection to the grid (minimizing all though feedback issue (once again, as an enginaster, I ignore the latency issues associated with such communications, and the associated feedbacks which would result).
To make these things work, I believe it will be necessary to put proximity sensors into all appliances in any micogeneration site. These sensors will provide input to the Microgen side of the equation to help it make predictions about what the unpredictable humans will do in the upcoming minutes. A body standing in front of the drier in time proximity to a washer that just finished (or is about to be unloaded) likely means the drier will turn on. Equally necessary will be the temperature sensors in the fridges and their set points to allow prediction of a compressor turning on. All of this data the Micro gen systems catalogs to give it a prediction of demand to allow it to calculate the feedbacks to the greater grid so it can inform the greater grid what the hell is likely to happen. The greater grid system assembles the information from the myriad microgen systems and issues orders to all the power plants to compensate taking into account the various feedback loops in each of those systems.
I am an Enginaster, Hear Me Solve....
I bet we can make the system to handle this better than we can make a computer model to predict the weather/climate.
I design motor control systems, and I know how extremely careful design is necessary to prevent instabilities with even as little as one milliseconds latency.
Apart from the mentioned hazards of microgeneration there are these:
1. The required equipment and installation are expensive.
2. The payback time due to energy "savings" is longer than the replacement time of the equipment.
3. The government usually encourages people to install said equipment by means of income tax deductions on a percentage of the installation cost.
4. One of the effects of microgeneration is to increase the cost of centrally generated electrical energy due in part to all the modifications required to add some "brains" to the grid to make it intelligent and to maintain those existing generators running in case the microgenerators stop microgenerating (wind and sun are unpredictable.)
As a result of the above, only the well to do can afford to use microgeneration. The poor and most of the middle classes are out.
In other words, mostly the people who are the least in need of cheap energy are the ones who can afford the benefits from microgeneration and to add insult to injury, the rest of the masses help them do it by paying part of their installation costs at the same time that their energy bills increase due to their generosity!
I accept some of the above. My company doesn't make solar panels and markets only to countries with predictable hot sunny climates. For the uk and other grey rainy countries I have hopes for the prospective new Hyperian mini reactors due, we hear, to be experimentally installed in Britain in 2013.
It does seem a lot simpler and safer to use home-generated electricity for heating air and water and leaving the clever alternating current to proper power stations.
Well there is such a lot of sunshine energy going begging in some countries that it seems like a good opportunity to supply to the local grid, but for us in the UK since wind and solar power is not tenable, power stations it should be - I favour coal and nuclear.
I don't think anyone here will argue with the idea of using the sun to do anything. In the end it is the economics and fundamental mechanics that make me grimace.
Subsidies shift the Smithsonian Curves (Adam Smith that is) in directions that cause efficiencies not to be found.
Agree in spirit, but what's the point of generating (hideously inefficiently) electricity to convert into heat?
What's wanted is a resonably benign salt with nice high latent heat and a melting point of around 85º (higher would pose problems with working fluids). Stick a couple of cubic yards in the cellar with LOTS of insulation and heat it from thermal panels (with, if necessary, heat pumps run off solar electricity). Most of the bits are off the shelf, so it might work OK in cases like my flat which is all-electric. Only trouble is, I haven't got a cellar!
-- Regarding the Grid controlling itself
Forrest Whitaker narrates a commercial for IBM discussing exactly my supposition above about the power lines acting as data communication lines and making the environmentally safe power options viable.
He conveniently leaves out the need for the cutoff switch the the grid needs to make the power control system work. i.e. the remotely operated switch which shuts off your AC when you need it.