It takes energy to produce them, sure, but it's way less than even just the production needs for coal or natural gas. Not to mention that's a one time carbon cost (per lifespan which is close to 30 years these days) vs ongoing emissions. And additionally, as the energy mix where the panels are produced cleans up, the carbon footprint of the panels go down as well! Is it the perfect solution? No, but there is no silver bullet to get off fossil fuels. Solar is just one part of that transition and it is exciting to see more groups exploring the solar/shade synergy (there's some cool shaded farming solar experiments going on that also make use of the solar panel's shadow for additional benefits!)