Step by step we are improving our infrastructure, learning out to manage the complexity of an off-grid facility, trying to get all systems working together harmoniously. The photo above shows a few of the elements: vehicles, our new garage and boatworks, our underground sewage treatment plant in the foreground, the grass covered berms we use to disperse water from the sewage plant, and our array of solar panels.
Most visitors to Hakai miss seeing the guts of the operation. Left to right: generator shed, energy management center, water treatment building, warehouse/shop, yet more working vehicles and the corner of our luxurious new bunkhouse.
Energy Production and Management
We run our own local electrical grid at Hakai, a system designed, installed and maintained by Hakai Energy Solutions (HES). The HES website and links therein explain the workings of the system in much more detail than I can get into here. It is a very innovative system, which has received considerable attention from the engineering community.
As you might expect, at the heart of the system is a network of specialized electronics–inverters and other devices. It looks a bit like the bridge of the Starship Enterprise.
The central resource managed by the grid are the storage batteries–effectively the energy bank. Our energy producers fill our bank account; all the electrical devices at Hakai–from light bulbs, to toasters, to iPads–deplete it.
Our 50 kilowatt solar array (see the photo at the top of the page) gets all the attention at Hakai, but we need our diesel generators for those long winter nights, or those rare days when we don’t have sunny skies at Hakai. Generator A fills in when the solar array cannot carry the load.
If you know anything about generators, you will notice that Generator A has a bunch of extra copper pipe attached and a heat exchanger on the exhaust pipe. That’s all to capture waste heat, which we pipe next door to the heating boilers, which are discuss below. They call this ‘cogeneration’. Here is a closeup:
Occasionally the system gets into a tangle, and we have to bypass the complexity of the system, and go back to basics. We fire up the backup, Generator B, pull the big red lever, and run for a while like everyone else does on the coast, with the generator speeding up and slowing down according to the load. Usually that is for only a short time. If we really got into a snafu–hasn’t happened yet–we have a third generator in reserve, which can keep the Headquarters building up and running until help arrives. That’s what you need on the Central Coast–defence in depth.
Cogeneration and Building Heating
Most buildings used in winter are heated via our central boiler and circulatng antifreeze (glycol) network. A large portion of the energy needed to heat this system is recovered from the Generator A (see above) via heat exchangers on the engine cooling system and exhaust. The pipes leaving the heat exchanger head next door to the storage tanks in the boiler room, then on demand out to the buildings that need heat. Typically the waste heat from Generator A is sufficient for our heating needs. If not, one of the diesel burners fires up to pick up the slack.
Photo shows: copper pipes from Generator A enter at the top left. Fluid heated if necessary by one of the two diesel burners then stored in the white tanks. At the right there are the five distribution lines that run in underground loops to the buildings that are heated by this system.
At Hakai we are blessed with abundant clean water drawn from the large aquifer that lies under the sandy expanse between Pruth Bay and the West Beach. A single well draws water from a depth of 8.5 meters, and has been verified to have ample capacity for sustained activity for our projected loads with no threat of depletion or salt water intrusion.
Although our raw water tests free from biological or chemical contamination, it is turbid from suspended sand and discolored by tannin from naturally decomposing forest vegetation in the bog forests that surround us. In order to deal with these defects (which are largely cosmetic) and to guard against any possible future contamination by microorganisms, we have commissioned a municipal water treatment system that includes the following:
- Ozone injection, which breaks tannins into simpler components and kills most pathogens
- Slow sand filtration, which uses a bed of living microorganisms found naturally in all water sources to purify the water
- Charcoal filtration, which absorbs other contaminants and provides the final clarification step
- UV treatment, which kills all remaining microorganisms
- Injection of a small dose of chlorine, which suppresses any growth of microorganisms prior to consumption
Warning: The outside faucets at Hakai supply untreated non-potable water unless otherwise labelled.
At Hakai we have taken particular care to ensure that our sewage treatment system guarantees that we have no negative impact on our land, our aquifer or the surrounding streams and ocean. We have implemented a centralized, site-wide BioNest sewage management solution on a scale that would be typical for a small municipality.
A network of sewers from each building converges at our main treatment center, which comprises a sequence of eight large buried concrete chambers. The heart of this system is the bioreactor. The bioreactor chambers contain a matrix of polymer ribbon that provides a substrate for the culture of microbes that biologically break down waste. Aerobic conditions are maintained via a bank of infusion pumps. Once treated, the clear and odorless waste water is dissipated on drip fields on four large sand berms using a process known as pressurized leach field dosing.
A four-chamber grease trap pre-treats the waste water coming from our main kitchen prior to its introduction into the main sewage system. The entire sewage treatment system is controlled by computer and can be monitored and managed remotely via the Internet.
Other Municipal Services
We have all the other services that the works department of a village would have:
Garage, mechanical workshop including welding capability, carpentry shop, concrete mixers, large and small excavators, Bobcat, dump truck, ATVs, trailers, chainsaws, whole range of power and hand tools. Our warehouse is our equivalent of the neighborhood hardware store.