This is indeed something we get asked from time to time. And the answer is yes, solar concentration is cheaper in many contexts. It depends on what you want to do with the energy.
Left: A student and I installing a PV system at a school in rural Nepal.
Right: Lytefire solar cookers deployed for a school in Kakuma, Kenya.
Cost Comparison: PV vs Solar Thermal
First, let’s have a look at the sheer cost of PV panels. Their costs have come down rapidly over the last years, but they are still hovering around 1€ per peak kilowatt [kWp]. It means that for a, say, 3.5kWp PV system, there is a minimum investment of 3500€. On top of that come the installation costs, which can be a significant cost (sometimes more than the panels themselves) plus the inverters. If one wants to add battery energy storage to the system, you can roughly double the cost again. That’s why most PV panels are tied to the grid. Many PV systems won’t even work if the grid is not functioning as they require the grid for their inverter to work.
So in summary for a PV system:
– 3500€ for 3.5kWp of PV panels
– 1500€ of rooftop installation minimum (including charge controllers, wiring, labor)
– (optional) 3500€ of battery storage
– (optional) the appliance to use the energy with (stove)
Total: 5000€ core costs for PV
Now let’s compare this to Lytefire. A 3.5kWp Lytefire PRO Solar Cooker costs 4350€.
So in summary, for a Lytefire Solar Cooker:
– The solar concentrator
– The appliance (stove)
– Installation (there are no special installation costs like for rooftop solar)
Total: 4350€
So today, Lytefire is 13%, or 650€, cheaper for the same output.
And keep in mind, this is comparing a globally industrialized product to a young, small-batch produced technology. And this is what excites me so much about Lytefire: We are at the very start of using solar thermal technology for baking, cooking and roasting, and we are already able to do it cheaper than industrialized PV can. And from here on, Lytefire can only become cheaper.
Plus we have a few other benefits (which are the reason we started this work in the first place):
– Locally maintainable: Users can actually maintain this tech instead of throwing it away and buying a new one when something breaks
– Local autonomy: Each unit creates the opportunity for solar, renewable and off-grid thermal power
– Support local economy: We focus on entrepreneurial clients and each unit creates a job and supports the local economy
– Low emission manufacturing: Lytefire has lower embodied energy than PV (less energy used to produce each kWp than for PV)
– No rare earth metals
Context: Heat or Electricity?
Secondly, we also must consider the context. The above comparison only works, if the primary use of the energy is for cooking, baking, roasting or other thermally intensive processes. And there it is not needed at all to use electricity to produce this heat. If you want to charge your phone, or have lighting: PV is the better option. If you want to bake, roast or cook, then Lytefire is the better option.
That’s just physics. Lighting and computers are very efficient in using electricity for the value they create, and ovens, well, they’re using an incredible amount of electricity. To charge a phone on a slow charger consumes 5W. A stove uses 1500W. So 1 pot cooking for 1 hour is the same amount of energy as charging 300 phones for an hour. That’s why we say: When it’s for heat, use a Lytefire. When it’s for digital and lighting: Use PV.
And in the end, the two are very complementary: We see this when we look at solar PV mini grids in Africa. When people use the electricity to charge phones, run computers or for light, the minigrid can serve hundres to thousands of clients. But when people start to cook and bake, the thermal energy required to do this quickly drains the minigrid. A combination of both PV for electricity and Lytefire for high-temperature heat has the best return.
What do you think? Care to comment?
More about Lytefire Tech: https://lytefire.com/tech
Lytefire PRO Solar Cooker: https://lytefire.com/lytefire-pro-cooker
