- Doris - A thought experiment in progress
- Doris - A thought experiment in progress (2) - Energy Delivery
- Doris - A thought experiment in progress (3) - Storage Sensitivity
- Doris - A thought experiment in progress (4) - You have to do both
- Doris - A thought experiment in progress (5) - Good and Bad Years
- Doris - A thought experiment in progress (6) - The Mix
- Doris - A thought experiment in progress (7) - Climate
It is important to remember that Doris is a computer simulation with some arbitrarily set parameters and rules, it exists only in the imagination and has no physical reality.
In most energy economies without a significant amount of storage, wind and solar generators are alternatives to those fueled by gas, coal etc. When the sun does not shine and the wind does not blow (as sometimes happens on a winter's night in December or January), the sustainable sources drop out and gas turbine stations kick in. Whilst this is not explicitly stated in energy policies, there is a in effect a duplication of generating capacities. This causes a variety of problems which include grid management where both demand and supply are related to the weather and economic ones. Investors in conventional generating capacity may not want to participate in a back-up system to a wind farm, they probably want a free standing investment.
Energy policies which attempt to have a degree of sustainability need to take account of the winter problem, Typically, this the time of year when the demand for energy peaks.
Storage at the household and some grid management at the neighborhood level might make a contribution. The graph below shows the daily demand for electricity as modeled in Doris, this is roughly 6.8 kwh/day scaled up to four household, the demand has peaks at the start of the waking day and in the evening. Say, each household has 10 kwh of storage, it could "download" its energy for the day over a six hour period by imposing a load of just over 1 kw on the grid. Resorting to the usual gross over simplification, if each household does this in turn, the demand is constant over the day and approximately 60% of the level that would be needed if storage was not present in the system.
In most energy economies without a significant amount of storage, wind and solar generators are alternatives to those fueled by gas, coal etc. When the sun does not shine and the wind does not blow (as sometimes happens on a winter's night in December or January), the sustainable sources drop out and gas turbine stations kick in. Whilst this is not explicitly stated in energy policies, there is a in effect a duplication of generating capacities. This causes a variety of problems which include grid management where both demand and supply are related to the weather and economic ones. Investors in conventional generating capacity may not want to participate in a back-up system to a wind farm, they probably want a free standing investment.
Energy policies which attempt to have a degree of sustainability need to take account of the winter problem, Typically, this the time of year when the demand for energy peaks.
Storage at the household and some grid management at the neighborhood level might make a contribution. The graph below shows the daily demand for electricity as modeled in Doris, this is roughly 6.8 kwh/day scaled up to four household, the demand has peaks at the start of the waking day and in the evening. Say, each household has 10 kwh of storage, it could "download" its energy for the day over a six hour period by imposing a load of just over 1 kw on the grid. Resorting to the usual gross over simplification, if each household does this in turn, the demand is constant over the day and approximately 60% of the level that would be needed if storage was not present in the system.
The upside of this scheme is that the amount of conventional capacity required is reduced and that the efficiency of most plant increases if it can be run at constant load rather than spinning up to take account of a period of light airs or a surge in the demand for hot water for tea making or spinning down when the sun comes out. Maybe, there is the need for some creativity in ways to channel investment in generating capacity into storage and energy management, this is a challenge but something worth evaluation.
A variation of this theme is the problem caused by solar eclipses. A recent eclipse during which the sun was obscured briefly over parts of Germany, which has significant solar generating capacity required some planning to avoid grid problems resulting from a sudden loss of power followed shortly after by a rapid surge.
Load management within the household could help reduce the peaks and troughs. From a limited and unscientific survey, most of the potential relates to cleaning operations. In many homes, the daily routine is based on meal times and these are more or less fixed. Devices like the washing machine and the vacuum cleaner can be operated at times which harmonize with the availability of energy, however, this does require some planning. I am intrigued by the concept of a robotic vacuum cleaner which comes out of its hutch when the solar panels are producing a surplus of energy and sucks up the filth from the living room.
I'm no advocate for returning to the living standards of our grandparents generation when running a household involved humping coal and ash, washing and cleaning were hard, monotonous work. But there was an appreciation of the seasons and the weather, if possible washing would be done on a "good drying day".
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