The heft and feel of a well-worn handle,
The sight of shavings that curl from a blade;
The logs in the wood pile, the sentiment of huge beams in an old-fashioned house;
The smell of fresh cut timber and the pungent fragrance of burning leaves;
The crackle of kindling and the hiss of burning logs.
Abundant to all the needs of man, how poor the world would be
Without wood.

Everard Hinrichs, quoted by Eric Sloane in A Reverence for Wood


Tuesday, June 28, 2011

Survival of the Smartest

A couple of months I posted an article called "Survival of the Fittest", in which I focused on three key ingredients of success in difficult times: people, products, and process. My friend Sita Warren recently brought to my attention a great example of a project that combined these three elements to establish a whole new way of thinking about the future of lumber drying.

The essential technical problem facing the lumber industry is that in the evolution from air drying to kiln drying, driven by the need to offer a wider variation of lumber products in a more timely fashion, the energy cost component of the process increased significantly. So much so, that lumber drying efficiency has become a differentiating factor in the success of companies across the industry. And energy prices will continue to force more and more lumber companies to find alternative drying solutions, or get out of the business.

In the vein of this dilemma, a team of folks came together to adapt a neat, low-cost technology called the SolarWall to the field of lumber kiln drying. The problem was how to capture the "free" energy of the sun, the same energy that was used in centuries of air-drying lumber, and bring it back as a cost-effective substitute for kilns fired by traditional fuels. Instead of high-costing photo-voltaic solar panels, SolarWall allows solar energy to be captured with technology that is more in the price neighborhood that typical lumber kiln operators could consider in new kilns or in retrofits to existing kilns.

This article describes how it does that, and how the team made it all come together. The article describes how the SolarWall works:
The demonstration kiln is manufactured out of a standard steel shipping container. It has standard sides all around, except for the side facing south (on the right side in picture), which has a Solarwall, which performs like a solar energy collector. But rather than delivering power, it heats air.
"A SolarWall solar air heating system comprises two key parts: perforated aluminum or steel cladding, installed on an exterior wall or walls (usually the sun-rich south-facing wall) and simple ventilation fans to draw the heated air into the space to be conditioned.
According to the company, SolarWall systems produce up to 600 watts/m2 (60 watts/ ft2) of thermal energy.
When the sun warms the surface of the SolarWall, heated air is drawn inside through thousands of tiny holes on its surface.
The system essentially takes the heat out of the air, heat that is provided, of course, by the sun. In the case of the BC Hydro pilot project, the solar-heated air is then distributed and re-circulated throughout the kiln, to help dry the lumber. In effect, the SolarWall system displaces the need for most of the heating in the kiln, meaning absolutely no natural gas will be required."
Like all great solutions that adapt technologies to new applications, the concept of bringing the "solar" back into lumber drying will be an incremental succession of improvements and hybridizations that eventually result in a paradigm shift in the prevailing business model: one that is greener, less costly, and meets the needs of the customer. As far as lumber drying goes, that can't happen any too soon.

To those who count out the solid wood industry in these increasingly difficult economic times, and maintain that substitute products are the wave of the future, I say:

Don't count us out yet. We've still got a few tricks up our sleeves.


Anonymous said...

Let's test these out in PA!

Anonymous said...

As usual, solar is only part of the answer to our green energy needs. Solar has proven to be more expensive than biomass and may not be economically viable without incentives or subsidies.

I would still like to see the use of high efficiency (85%) CHP technologies utilized in our energy demanding applications, such as drying, pellet manufacturing, etc.

In fact, it is very easy to combine the two technologies to take advantage of the solar energy and biomass. One can install a solar thermal collection field that heats thermal oil and utilize biomass to augment or substitute the hot oil to the required temperature. This combination allows solar to do the heating when available and biomass to carry the load during wanning solar times or at night to produce CHP 24/7. Organic Rankine Cycle (ORC) is a great technology for this solar/biomass combined aplication.

For those in the Northeast, we know that solar energy is very limited in applicability!