Because most appliances are too low consumption and constantly cycling to work directly off a gasifier. Plus they require very clean gas. The gasometer allows to pull rapid and high volume of gas for storage to supply the lower volumes needed for most appliances. In any case you would still need automation even if you could run directly of the gasifier you would need to fire the gasifier up, get a flare lit and then direct the gas the appliance at the right presure and volume.
I already have controls that can do all this.
To understand you must see the full picture. For an off grid system running on charcoal for electric power. You need charcoal right? Why waste energy in heat loss or create a complicated heating system to create charcoal and still lose a lot of energy?
The point of this is to also create charcoal for your charcoal generator for electric power while making gas for more efficient gas appliances. A daily allotment of charcoal production to sustain electric charging is just as much the goal as running these appliances on gas. The gas appliances reduce your electrical need and do so more efficiently. So now you have less charcoal you need to make. Less fuel as a whole you need to make, thus making going off grid with woodgas much more viable with the benefits of a charcoal stationary gasification unit.
Think about it. Say we are just running a hot water heater. If you use electric then you must convert the gas to electric right? How do we do that? We run a engine powered generator and we lose 75% of the gas energy potential in just that conversion. Now if you have a battery bank and AC inverter you have more losses. Then when the electric gets to the hot water heater what are we doing? Converting again from electric to heat!!! Why?? Kinda dumb when you can skip all that and just run that gas in a gas hot water heater; its a HUGE efficiency gain. It is time to break the mold!!
The cost for this entire system would cost less than a direct gasifier system counterpart that can only run an engine. We are no longer trying to build a complex high performance gasifier for engine fuel. It can be done much simpler and you are only building a simple gasometer that is basically taking the place of the filtering system as it is the filter. The automation cost is more than justified. Then you have the charcoal gasifier thats a no brainer. They are a fraction of the cost and far less complex, less maintenance, no tar etc.