Learn Hardcore Japanese: osen wo herasu taisaku tosite, yane ni taiyoukoupaneru wo tukeru keikaku desu. - As a measure to reduce pollution, we plan to put solar panels on the roof.

Breakdown of 汚染を減らす対策として:
• 汚染を減らす – a relative clause (“to reduce pollution”) modifying
• 対策 – “measure(s)”
• ～として – an adverbial marker meaning as
Together, 汚染を減らす対策として means “as a measure to reduce pollution,” functioning as an adverbial phrase that sets the context for the main clause.

Why is 汚染を減らす using 減らす (with を) and not 減る (with が)?

Japanese distinguishes transitive/intransitive verb pairs:
• 減らす is transitive “to reduce (something),” so it takes を for its object.
• 減る is intransitive “to decrease,” taking が for its subject.
Here the action actively reduces pollution, so 汚染を減らす (transitive + を) is correct.

What does として mean here, and how is it different from ために?

• として means as, indicating the role or categorization (“as a measure”).
• ために means in order to, expressing purpose.
If you used 汚染を減らすために, it would stress “in order to reduce pollution (we will do X),” whereas ～対策として simply classifies the plan as one of the measures.

Why is 屋根に used with the particle に in this sentence?

The particle に marks the location where an action takes place or where something is attached/installed. In 屋根に太陽光パネルを付ける, 屋根に means “on the roof” – that is, the place where the solar panels will be mounted.

What kind of word is 太陽光パネル, and why is part of it in katakana? Could we say ソーラーパネル instead?

太陽光パネル is a compound noun:

太陽光 (たいようこう) = “solar energy” or “sunlight” (Sino-Japanese)
パネル = “panel” (a foreign loanword, so written in katakana)
You can also say ソーラーパネル, which is a full loanword from English. Both are understood; 太陽光パネル often appears in formal/technical contexts, while ソーラーパネル sounds more casual or conversational.

In 太陽光パネルを付ける, what does 付ける mean? Could we use 取り付ける or 設置する instead?

• 付ける here means “to attach” or “to affix.”
• 取り付ける (とりつける) also means “to install/attach” and is slightly more formal.
• 設置する means “to install” in a more technical or official sense.
All three verbs work, with nuance:
– 付ける = everyday, general “put/attach”
– 取り付ける = more specific/formal “mount/install”
– 設置する = most formal/technical “set up/install”

What is the grammar behind V-plain + 計画です, and how does it differ from V-plain + 予定です?

• V-plain + 計画です expresses “It is a plan to do V.” It often feels like an outline or proposal, sometimes long-term or formal.
• V-plain + 予定です means “It is scheduled/expected to do V.” It usually implies a more definite, near-term arrangement.
In our sentence, 太陽光パネルを付ける計画です conveys “There is a plan to install solar panels,” with a nuance of official planning rather than a firm schedule.

There’s no explicit subject in this sentence. Who is making the plan?

Japanese frequently omits the subject when it’s understood from context. Here the planner (e.g. “we,” “the company,” or “the municipality”) is implied. To specify you could say:
• 私たちは屋根に太陽光パネルを付ける計画です。
• 会社は屋根に太陽光パネルを付ける計画を立てています。
but omitting the subject is perfectly natural when it’s clear who is responsible.