我们国家政府有个政策，那就是；谁家如使用电量不超过90单位，其家就免付电费。我来自泰国。

Arthur is very good, however, If I were him, I would write: 我们泰国有这样的政策：如果谁家使用的电量不超过90个单位，那么这家就不需要支付电费。 Or, more formal: 在泰国，如果某一家庭所消耗的电量小于90个单位，那么这个家庭就会享有由政府提供的电费免付待遇。

Incidentally: 把垃圾分类, la ji, 来is lai. I guess it's just a typo, because it's very obvious that your Chinese is already at an advanced level. You're staying in China now, if I say ordinary Chinese people cares very much about the enviornment, I don't think you would agree with me, haha! However, I noticed... 在香港机场，工作人员会回收乘客剩余的食物，并将它们加工成肥料，用于机场周围土质的改善。这一措施大大提升了香港机场的绿化景观效果。令所有在香港机场登机的乘客都能够感受到香港不仅是一个现代的亚洲国际都会，同时它也是一个充满绿色、生机盎然的美好家园。 Actually I wrote this to challenge your Chinese reading, lol. I guess this is exactly the reason why you raised this question. These sentences I wrote are very formal, like newspapers. What do you think?

限制塑料袋的使用，使用购物袋，可降解的包装袋等

比如说 洗完头的水 或者洗菜的水会用来冲厕所