The problem is the origin and forced labour.

Most of the cheap panels in storage are made in China, while the European manufacturer’s cannot produce at the same price. China also uses Uyghur forced labour to get those low prices www.bbc.com/news/world-asia-china-57124636

So making them cheaper is not really an option, unless the EU also wants to go for forced labour camps to compete with China. But it could work the other way around by adding tariffs to Chinese panels or restrict imports if there is a connection to forced labour. The US already added tariffs to Chinese solar panels last year and expanded them reuters.com/…/us-says-solar-imports-four-southeas…