Although some of this information is not immediately pertinent to the Energy Project posters, here are a few sites intended to help people create posters for scientific research presentations. (The main difference is that you are not presenting original research, which affects what some of the appropriate subsections should be.)
You’ll notice a wide variety of examples and even some conflicting advice (for instance, Colin Purrington is not a fan of the portrait layout for posters, while Better Posters features one as an example of good design.
In the end, you have significant latitude simply to do what makes sense for the work you are presenting. But these sites provide lots of ideas, thoughtful critiques, and resources that you may find helpful.