Developing World Electricity Concepts

[Sceadwian]

A central inverter and battery storage bank at the generator itself would be even simpler than that.

 

[morg]

Kchriste: It is an obligation of the funding package that the hydro plant tap all available capacity first time ... I'd rather leave capacity expansion out of this discussion. I admit the idea has some merit though, and I'll speak to some of the accountant types about it. Water resource is becoming increasingly variable however due to deforestation and global warming. This might mean it's best to invest the money in storage as a way of increasing reliability.

The more I look into synchronising inverters the more pricey it looks. From a user point of view though I still stand by the concept - the ability of the individual to take control distinct from the collective gripes of the community will be a great bonus to individual satisfaction levels. Kind of a communist-capitalist system: recognising inequality without threatening the equal stake of the poorest.

Anyone got any thoughts on a super-cheap (possibly clip-on) peak meter ?

Anyone got any information on the Gemini Converter ... or line-commutated inverters ?

 

[morg]

Sceadwian: Central battery storage is undoubtedly more economic ... though the costs have to borne by the whole community, including the poorest who have less need for the power. The result would still mean that no-one could boil a kettle - as it is unlikely the capacity could be more than doubled. Even if it could, they'd probably all need to boil at the same time to ensure they got their share before the battery went flat ... just doesn't sound too workable.

Grid capacity expansion is really a separate project.

 

[Sceadwian]

The costs need to be borne to the community on a usage basis. Charging a flat tarif for power is one of the major problems. Basic metering and charging on a per usage basis (with exclusion for mistakes) will regulate the power usage on a social level. People will find other ways or use their power more efficiantly if they realize how much they have to pay for it. Though there should be some typical services that should be available to people that don't. And it's NOT capacity that's the problem, it's peak demand. Battery systems can be designed around the peak demand and are scaleable to provide 2 3 or however much extra power over the generateable as is required. Ideally the generator should NEVER be lightly loaded, there should always be some atempt in off peak hours to store that power in some way. Maybe a community water heater or electrolsys system to generate hydrogen and oxygen for a fuel cell system or for direct combustion.

 

[Oznog]

The line synchronizer thing separate from the inverter is not really possible. The point at which the AC is generated has to be the point at which the AC phase and voltage is synchronized with the AC line.

Well ok technically you could generate 110VAC with the inverter, rectify it back into a DC rail, then make a second inverter which generates AC again but synchronized, but that's a fairly roundabout way of doing it.

The synchronizing inverter is called a Grid Tie Inverter. People with solar panels or whatever use them all the time. They are fairly expensive.

 

[kchriste]

I admit the idea has some merit though, and I'll speak to some of the accountant types about it.

When you think of the dam as a large battery that will require no more maintenance than it does now, it beats any battery system hands down. Any electrical storage system is just a stop gap solution that will fall appart when the average capacity of the system is exceed. Using a storage system will just result in people using more power until the system is maxed out at 100% 100% of the time.

This might mean it's best to invest the money in storage as a way of increasing reliability.

There was an article I read recently of someone who had converted a Toyota hybrid Prius into a 15Kw UPS for his house. It's a little to rich for that area of the world though.
Globally, I think the real isssue is just too many people chasing dwindling resources. This is especially true in the energy hogging western world. The real long lasting solution to your problem, and the worlds, is population control.

 

[The Mad Professor]

I would seriously consider the suggestion made by "Kchriste" of using a 2nd turbine rather than implement an electronic techo fix that is not really going to sustainable at a local level. I'm kinda surpised that no one has suggest hydroelectric pump storage as an alternative method to battery and inverters, the practice is well proven by its larger cousins such as Dinorwig and the Snowy mountain facilties and I see no reason why it cannot be scaled down.


Incidentally , the turbines I presume these imported at great expense. Have any attempts been made to duplicate them by local craftsmen?

Off Topic Suggestion would be to recover methane from organic waste and store this to run an engine/ generator of some sort.

 

[morg]

Guys PLEASE .... I don't want to spend all my time negatively saying why things can't be done, I'm asking you for detailed electical input not a brainstorming session on what you would do if you were me. I've said it a few times - I don't want to discuss grid capacity expansion here.

Micro Hydro projects are 'run of the water' - drawing from a wier rather than a dam - so no hydroelectic pumping. As I said before - the technology (including indigenous turbine manufacture) is not a problem. It is a mature system with national standards. Extensive hyrdrology studies are carried out before funding is approved and the maximum capacity of the stream is tapped. I will look into the financial feasibility of 'over-drawing' this resource for peak periods but in the changing climate/deforestation it may lead to a largely redundant and expensive extra turbine. Can we leave this point here. Distribution is the project area.

In-home storage with a view to temporary power increase - with or without inverters - is the brief. If village capacity is subsequently increased, great, the distribution system is still valid.

If synchronous inverters are a no-go, does anyone have any other suggestions as to how a 400W supply can be upped to a 1000W supply temporarily ?

 

[Nigel Goodwin]

If synchronous inverters are a no-go, does anyone have any other suggestions as to how a 400W supply can be upped to a 1000W supply temporarily ?

Use a UPS type system - no sync required because the house always runs from the output of the inverter, and the incoming mains simply charges the batteries that feed it. Under low load conditions the batteries are on charge, with the inverter effectively fed from the incoming mains as well - as load increases it will start to draw power from the battery rather than charging it.