Google search will block your IP address temporarily if you use a download utility like wget to download search pages for scraping Google. However, if you run the scraper on Google servers itself through Apps Script, the request won’t be blocked as the IP address of the scraper would be one of Google’s own IP address.

The other alternative is Import HTML, a Google Docs function that you can used to scrape Google search results inside a Google Sheet.

function scrapeGoogle() {
  var response = UrlFetchApp.fetch('http://www.google.com/search?q=labnol');

  var myRegexp = /<h3 class=\"r\">([\s\S]*?)<\/h3>/gi;

  var elems = response.getContentText().match(myRegexp);

  for (var i in elems) {
    var title = elems[i].replace(/(^\s+)|(\s+$)/g, '').replace(/<\/?[^>]+>/gi, '');
    Logger.log(title);
  }
}