Survey results

The summary

Most answers so far are coming from developed countries, so this survey does not give a representative global overview at the moment.

The typical user

according to the survey is a Private Owner, builder and operator, handyman. Hydropower engineers come next.

Most systems are for 1 household.

This explains why there's not need for an ELC above 30kw. Most demand is 3kW - 30kW.

The 4 answers from developing countries are typically 5 - 9 househoulds, and the power is more towards 30kW.

Buy or build

More than half of buyers are willing to do some degree of assembly themselves, if they can save costs.

This matches with the interest for an open source ELC.


The most important "additional" feature is protection mechanisms. This implies a mains relay of some sort, some backup dump load bank, possibly an electrical water valve.

Second most interesting feature is dump load check.

Typical problems

with existing ELCs:

- too slow. This underlines the need for a well tuned P and I value. The hydrocontrol has a built-in P-I tuning wizard.

- either humming because of phase angle switching or flickering because of full cycle switching.

YES :-) you will have to suffer one or the other. The best solution have found so far: control only one channel with phase angle, and the rest with full cycle. There in an option in the menu to go completely full cycle, if required. PWM would be a solution, but that's a new field for me.


There is a market for the hydrocontrol with all of the optional features, but it's very small.

A "simplified hydrocontrol" with smaller PCB and less parts would have following advantages, and appeal to more users:

- cheaper if bought completely assembled

- easier to build yourself

- still has all of the most relevant features.

The original task of the survey was to decide on the way forward for the hydrocontrol PCB.

It seems for now that neither for the "big" hydrocontrol nor for the "simplified" hydrocontrol there is a demand for 100 pieces of a fully assembled PCB.

So it's back to hand-soldering again :-) I will get small batches of 10 naked PCBs made as needed.

Also I will design a smaller PCB, and publish all the relevant files.

Detailed results

16 responses