Q: How much does a greenhouse solar kit cost? A: $300–$1,000 for small setups, up to $2,500 for full off-grid systems. Many fans and lights can run on 12 V DC directly. Site Preparation and Foundation Excavation and Leveling: Preparing the site can cost anywhere from $500 to $2,000, depending on slope, soil type, and. Solar greenhouse pricing depends on two things: how big the structure is and how “hands-off” you want the climate control to be. Here are realistic ranges most gardeners land in: Basic panels, a modest battery bank, charge controller, wiring, and a simple fan/light setup—ideal for a typical hobby. Small backyard models (under 100 sq ft) may cost as little as $1,500, while larger, high-tech greenhouses (400–800 sq ft) with automated systems and full solar integration can exceed $15,000. Mini Greenhouse (under 100 sq ft): Seedlings, herbs, basic season extension. Standard Backyard Greenhouse. The initial cost of installing a solar-powered energy system for your greenhouse can be significant, but the long-term savings it provides can't be ignored. Factors such as location, permits, and installation requirements can also lead to variations in overall expenses. Costs for glass can vary from $10 to $30 per square foot, depending on the thickness and quality.