Starting buffer storage
Add cheap and small storage building. They have one input and one otput and have footprint of 3x3 cells. For building them you use some iron and mechanical parts. They work without electricity, but slow (throughput without electricity is half unit). I think that small staring storages can be useful for reducing fuel consumption. Also they can work as buffer storage for intermediate products. One production building is slow and produce relativety large amount of product, but next factory process that product in small amounts fast. They build and process same amount of product on large time. You can get situation, where first building output is clogged, while next processing small amount of that product. So you use small buffer storage to store it.