Build a Solar Food Dehydrator

Image Gallery With increasing interest in healthy eating, sustainable local food supplies and self-reliance, many people are discovering the benefits of a solar food dehydrator. EBEN FODOR

More and more people are recognizing the importance of food quality in their daily lives. The freshest, ripest, tastiest and most nutritious food comes from our own gardens or local farmers. But because these high quality fruits and vegetables are seasonal, you have access to them for only a few weeks or months each year.

What do you plan to eat the rest of the year? Will you rely on industrial foods grown by strangers from all over the world and shipped thousands of miles? With increasing interest in healthy eating, sustainable local food supplies and self-reliance, many people are discovering the benefits of a solar food dehydrator.

Solar food drying is more than a curiosity or hobby — it’s an ideal application for solar energy. Solar radiation passes through the clear glass top of a wooden dehydrator box, then the heat trapped by the box dries the food. The dehydrator also may have an absorber plate inside, which indirectly heats your food and creates a convection current of air that enters a vent at the bottom of the dryer (see illustration). The cool, fresh air that enters the vent heats up, circulates through the dryer, then exits through a vent at the top. As your food dries, moisture is carried away with the hot air. But do solar food dryers work well? Are they practical? Yes, but first let me put this topic in the context of creating a healthy and sustainable food supply.

Eat in Season Year-round

Food preservation is the key to extending the summer’s precious bounty of locally grown produce throughout the year. If you’re like me, you would prefer a method that’s easier and requires less energy than canning.

Freezing is commonly viewed as the most convenient preservation method, but freezers require a constant source of electricity. Your food will be vulnerable to power outages and mechanical failures, and freezer burn will limit the storage life of most foods to about six months.

Drying is an excellent method of food preservation that maintains a high level of flavor and nutrients, while providing a convenient, compact, easy-to-store supply of your favorite produce. Electric food dryers work fine, but I don’t care for the constant noise, heat and odors they add to my house. Electric dryers also take away valuable counter space for weeks on end and can attract ants and other pests. The electricity to run them costs about a dollar a load. The convenience of electricity does not compare to the satisfaction of drying food with free solar energy.